Phase one of the NSC opened in 1991, and the centre has been a moving target for upgrades and expansions ever since. It is owned by the Department of Education, Sport and Culture and run by Manx Sport and Recreation. In December 2001 the centre earned its first Quest accreditation, the UK quality scheme for sport and leisure, and has maintained its highly commended status ever since. Three years before that mark, the venue hosted parts of the 2001 Island Games and provided the stage for the closing ceremony. In August 2007 the NSC took the runner-up award in the European City of Sport competition, judged by assessors from the European Capitals of Sport Association. By 2008 it was on the British Olympic Committee's shortlist as a possible training venue for the London 2012 Games, named for road cycling, mountain biking, handball and shooting.

The centre's busiest week of any year may be the Manx Youth Games, an annual island-wide schoolchildren's competition where the opening ceremony fills the athletics stadium and twelve different sports run simultaneously across the venues. The bigger moment came in September 2011, when the Isle of Man hosted the Commonwealth Youth Games. The NSC's Bowl Stadium staged the opening ceremony on 7 September and the athletics stadium hosted all the athletics events. The swimming pool ran the swimming competition. The main sports hall, fitted out with seating for 1,000 spectators, became a badminton arena. For a week, a 27-mile-long island in the middle of the Irish Sea operated a small-scale Commonwealth Games of its own, and the NSC was the engine room.

The 2010s were not kind to the building. A flood damaged the site in 2015, and a fire broke out in March 2018. That August the swimming pools closed for a nine-month, four-point-two million pound refurbishment that included replacing the movable floor in the competition pool and rebuilding both flumes. When the works finished, the centre regained the gear it needed to host another generation of Manx Youth Games swimmers, plus a steady stream of school lessons, fitness classes and casual lane swimmers. In 2009 the Isle of Man Institute of Sport, the body that supports the island's elite athletes, had moved into a new purpose-built facility at the athletics stadium, anchoring the centre as the island's high-performance hub as well as its community sports house.

The athletics stadium has a six-lane synthetic track (eight lanes on the straights), an eleven-metre hammer and discus cage, floodlights and a 500-seat grandstand. The track holds a current United Kingdom Athletics certificate. Inside, the main sports hall can be divided into ten badminton courts and serves as everything from a five-a-side football venue to a netball arena. The secondary hall takes four more badminton courts and doubles as practice space for indoor cricket and archery. The Bowls Hall holds five rinks, with portable seating that can be expanded to accommodate 100 spectators for tournaments, and is home to the Isle of Man National Sports Centre Indoor Bowls Association. The Squash Centre has six courts, four with glass backs, three of those portable so that show-court configurations can be built up for major matches. A Fitness Zone gym, sauna, steam room and whirlpool round out the dry side. Holding it all together is the atrium bar and cafe between the pools and the dry facilities, with windows looking out onto the running track.