The first of those tours finished with a remarkable series victory while the second ended in disappointment as the Lions fell just short of what would have been only their second Test triumph in the Land of the Long White Cloud.
Underwood's Lions career began in style as the then 25-year-old scored a brace of tries on debut against Western Australia. Two more followed just over a fortnight later when the Lions beat New South Wales B 39-19 five days before the first Test in Sydney.
Underwood won his first Lions Test cap on July 1 but the celebration didn't last long as the tourists were hammered 30-12 in the opening Test of the three-match series. Better was to come, however, as the Lions bounced back to record a 2-1 series win, with Underwood playing his part.
Four years later and Underwood was back in action with the Lions, featuring in all three Tests alongside Gavin Hastings and Ieuan Evans in a cosmopolitan back three, just as he had done in Australia.
Again the Lions were defeated in the first international and again they hit back to win the second, with Underwood claiming the game's only try in a 20-7 victory at Athletic Park in Wellington. Unfortunately, Underwood's Lions career came to an end without a second series win as Ian McGeechan's men fell to a 30-13 defeat to New Zealand in his final match as a Lion.
Outside of the Lions, Underwood was England's record appearance holder before Jason Leonard, winning 85 caps between 1984 and 1996.
He still holds the record for the highest number of tries in England colours with a total of 49, a figure that sees him sit joint third on the all-time list of try scorers in international rugby.
In 1992, he and brother Tony became the first brothers to represent England since 1937, while few England fans will forget his mother's Twickenham celebrations whenever either of her sons crossed the whitewash.
Previously a pilot in the RAF, Underwood now works as a management consultant and is a member of the Board at his beloved Leicester Tigers. The 47-year-old is held in particularly high regard at Welford Road where one of the stadium bars is named after him.
Rory Underwood factfile
Date of birth: June 19, 1963
Clubs: Leicester Tigers, Bedford Blues
International caps: England 85
Height: 5ft 9in (1.75m)
Weight: 13 stone 7lbs (86kg)
Underwood's Lions lowdown
Lions debut: Versus Western Australia, June 10, 1989
Lions Tests: 6 (All three Tests in Aus in 1989 and NZ in 1993)
Lions non-Test appearances: 9
Total Lions appearances: 15 (8 in 1989, 7 in 1993)
Lions points: 35* (seven tries) *under the current scoring system
Final Lions appearance: Versus New Zealand, Auckland, July 3, 1993
Rory Underwood was a series winner with the Lions in Australia 21 years ago
On a second Test victory over the Wallabies in 1989
"That has to be one of the most memorable moments of my career. The sheer relief, the joy at having turned round the fortunes of the tour in a week.
"The Grand Slam is a longer drawn-out affair, whereas in Australia we went from agony to ecstasy in a few short days. It was brilliant.
"Even better, we had the time to enjoy it because the tour schedule provided for a break of a week, part of it on Queensland's Gold Coast, before the third and deciding Test back in Sydney. Everyone enjoyed the moment, even those in the stand, and we realised that we were back on course to take the series."
On scoring a crucial try in the second Test win in New Zealand four years later
"The All Blacks kept coming but we smashed them back, we held them at a critical five-metre scrum where Jason Leonard proved his worth at tight-head, the two Martins (Bayfield and Johnson) dominated the lineout and, when a bit of loose ball appeared, I was bale to help the tabloid headline writers into 'Rory Glory' mode.
"When Sean Fitzpatrick dropped the ball, Dewi Morris saw the space on the blindside immediately. We had depth to our attack, Jerry Guscott drew the cover and gave me the space to get round John Kirwan and beat John Timu for pace.
"All I could think of in those 40 yards was the need to get the ball down because I knew how important a try was at that stage, so when I could see the line I took off into the worst dive for the corner ever. Whether I could have got nearer the posts to help the conversion I don't know and to be honest, it didn't seem that important."
On a personal and team triumph in that Test
"As I was running back I raised an arm in salutation to the boys in the stand. I knew how tough it had been for them. They had been putting in the work, they had been beaten, the press was starting to give them a lot of stick and they, as much as us, needed the tonic of a Test win.
"We retreated to a brilliant atmosphere in the changing room; there was relief, delight, the knowledge that we had achieved the win we felt we had been there in the first Test and how well everyone had recovered after the traumas of the previous fortnight.
"I was happy with my game too. I had felt involved all the time and if we were on a high, we soon discovered how much it meant to the people back home. The sports pages had been filled with gloomy news of the England footballers and cricketers and now here was a team doing well in the backyard of one of the game's traditional top teams."
On an eventual series defeat against the All Blacks
"It was hard to hear the All Blacks talk themselves up when it was all over. Sean Fitzpatrick, their captain, sounded very patronising when he thanked the Lions for bringing the best out of New Zealand and both he and Laurie Mains, the coach, went on to say that they had not enjoyed the series until the final hour - the part that they were winning.
"They implied that we had been guilty of negative play as opposed to acknowledging that we had played well, or had not allowed them to play well.
"For all that, I enjoyed my second Lions tour. I enjoyed the company of the players, the fun and good humour which helped strengthen squad spirit."