After successful stints with North Dakota State and Eastern Washington, Giacoletti was named the head coach of the University of Utah Utes. He replaced the legendary Rick Majerus, who retired in the middle of the 2003–2004 season. In his three seasons at Utah, Giacoletti led Utah to a 54–40 (.574) record.
In Giacoletti's first season, the Utes went 29–6 (.829) and won the Mountain West Conference regular season championship. After beating UTEP in the first round, the 6th seeded Utes upset 3rd seeded Oklahoma in the 2nd round to advance to the NCAA Sweet 16. It was the school's first Sweet 16 since the 1998 season, when Utah finished as the NCAA runner-up to Kentucky. Ironically, it was Kentucky who would beat Utah once again, ending the 2nd winningest season in school history.
During Giacoletti's tenure, Andrew Bogut was named the John R. Wooden Award winner and became the #1 draft pick in the 2005 NBA draft – joining fellow University of Utah student-athlete Alex Smith as the only time that two athletes from the same school were selected #1 in their respective drafts in the same year. Giacoletti was named the 2005 Mountain West Coach of the Year, after guiding the Utes to a 13–1 conference record, the best record in conference history.
Giacoletti's second season was dramatically different from his first. Gone was All-American Andrew Bogut, starting point guard Marc Jackson graduated, Justin Hawkins decided to transfer to New Mexico State and Richard Chaney transferred to Troy State, all major players in Utah's Sweet 16 run the season before. The Utes struggled with a young team and finished with the school's first losing record since the 1989 season, with a record of 14–15.
Giacoletti's third season saw a further decline and the Utes had their worst season since 1983–84 (11–19). His approval rating among fans plummeted and many Ute fans sought his resignation. There were even a few anti-Giacoletti web sites that popped up including Giacolettimustgo.com. A day before Utah's final regular season game, versus conference rival BYU, he resigned as Head Basketball coach effective at the end of the season.
At Drake, Giacoletti's teams got worse each season, just as at Utah (based on won-loss records). He resigned after 3+ seasons at Drake with a 32–69 record.