Tino Best made his debut in first-class cricket on 25 January 2002, playing for Barbados against Guyana in the Busta Cup. He opened the bowling with Ian Bradshaw and in the first innings took four wickets for 50 runs (4/50), and Barbados won the match by 162 runs. Best finished his debut season with 17 wickets from 5 matches at an average of 24.29 with a single five wicket haul.

At the time of his Test call up for the Test series against Australia, Best was Barbados' leading wicket-taker in the Carib Beer Cup for the 2002/03 season with 39 dismissals. Though Best was originally drafted in as cover for fast bowler Jermaine Lawson who had chicken pox, when Best made his debut in the third Test he opened the bowling with Lawson. The West Indies lost and Best bowled twenty overs without taking a wicket.

After an ineffective first Test, Best was overlooked for the West Indies' overseas tours and drifted out of contention with the emergence of fellow fast bowlers Fidel Edwards and Jerome Taylor. Back at domestic level, he fell out of favour and struggled to be selected for Barbados' Red Stripe Bowl side. While he was infrequently chosen for the one-day team, he improved on his previous season's wicket tally in the first-class competition and finished with 49 wickets including three five-wicket hauls, and was rewarded with a call up to the West Indies side to face England in March 2004. Best's first international wickets came in his second Test, the first in a four-match series against England; his maiden dismissal was that of batsman Graham Thorpe. England won the series 3–0 and Best finished as the West Indies' leading wicket-taker in the series (and third overall) with 12 from four matches at a cost of 25.08 runs each.

Between June and August 2004 the West Indies embarked on a return tour of England. Best played in the Lord's Test and was stumped off Ashley Giles' bowling after some banter from Andrew Flintoff wound him up sufficiently to try to slog the ball into the windows at Lord's. During the match Best suffered a back strain and was unable to take part in the rest of the series. It was hoped that the fast bowler would recover within a month, however the injury was more serious than initially hoped and he did not play cricket again until March 2005. In the Second Test against Pakistan in June 2005, after a wicketless first innings – where he had Kamran Akmal caught off a no-ball – and a second innings spell of 5-0-30-0, Best took four wickets in 11 balls, as Pakistan faltered from 223 for 4 to 309 all