United! follows youth football team Bank Vale United's attempts to improve their fortunes by buying a player from a rival team. Despite the fact that their team is amateur, United's impetuous striker Kevin Ripley believes there is no reason why they cannot pay for someone to come and join them. Kevin's team-mates Keith Nash and Gary Ansell, although sceptical, agree to the plan and the boys manage to raise the princely sum of £1 to purchase the talents of Nick Abel-Smith.
Despite Nick's obvious ability he is an unsettling influence and the Bank Vale players have to make a tough choice between success and loyalty. In addition to the usual football action Hardcastle includes a section on another of his interests, Motocross.
Consisting of six half hour episodes, the series followed Sheffield United as they chased promotion from Division Two, with the final episode focusing on the final games of the season as they achieved this ambition. Each of the episodes concerned one element of United the cameras were given full behind-the-scenes access to the club's inner workings.
Each episode focused on a specific element of the club:
Debuting on 6 April 1990, the series was first shown on BBC Two with each episode airing at 9pm on successive Fridays.