He played for the Croatia national football team (53 matches/2 goals) and was a participant at the 1998 FIFA World Cup, where Croatia won the bronze medals, and at club level he played for Hajduk Split and, most notably, Derby County.
Štimac arrived at the Baseball Ground on the 31st October 1995 for a fee of £1.5million from Croatian club Hajduk Split. He scored a goal on his debut for the Rams away at Tranmere, but the Rams fell to a heavy 5-1 defeat. The rest of the season was more successful: Derby gained promotion and remained unbeaten in 20 consecutive matches.
Igor Štimac had nearly four years with the Rams but the end of his Derby County career came as he was criticised from certain quarters in the club for not playing enough games. He was sold on 29 August 1999 to West Ham United for £600,000, where he scored once against Newcastle United.
In all, Štimac made 84 league appearances for the Rams, in addition to 7 FA Cup appearances and 2 League Cup appearances. In 2009 he was voted into a fans' greatest ever Derby County team, by readers of the Derby Evening Telegraph.
Štimac returned to his native Croatia and took over as manager of Hajduk Split. In the spring of 2006, he also spent two months coaching Croatian first division side Cibalia. He is currently also working as a co-commentator at the Croatian Radiotelevision during their broadcasts of the Croatian national team's matches.
Following his career in football he had a short spell as a popstar releasing a song called Mare i Kate.