|Competitor for Yugoslavia|
|1956 Melbourne||Team Competition|
|1950 Vienna||Team Competition|
|1959 Beirut||Team Competition|
At the age of 18, Kačić played for the Yugoslavia national water polo team at the 1950 European Water Polo Championship at which the team won bronze. During the 1950s he became out of favour with Yugoslavia's communist regime and had his passport confiscated on three occasions. He was jailed by the regime in 1952 which prevented him from joining the national team at the 1952 Summer Olympics. He was also kicked out of university.
He competed with the national team at the 1956 Summer Olympics, during which his friend and teammate Ivo Štakula defected to Australia. In 1957, he was awarded the Sportske novosti Croatian Sportsman of the Year. At the 1959 Mediterranean Games he won a gold medal. On the club level he was a long-time member of Croatian waterpolo club Jug from Dubrovnik, multiple national champion.
In 1956 he finished a degree in law. He later finished a doctorate in law in 1965 at the University of Zagreb, specializing in maritime law. Kačić also writes about history. He has collaborated with Ivo Pilar Institute of History.
He was elected to the Croatian Parliament for the first time in the country's first democratic elections in 1990 as an independent candidate. From 1994 to 2001 he was president of the State Commission for Borders of the Republic of Croatia.
In 1994 he received the Croatian Olympic Committee's Matija Ljubek Award. He has served on the committee which gives out the Franjo Bučar State Award for Sport. Kačić still actively supports Croatian water polo, retaining a position in the Croatian Water Polo Federation and supporting the national team.
- "Olimpijske legende: Hrvoje Kačić". Olimp (in Croatian) (Croatian Olympic Committee) (15). June 2005. Retrieved 23 May 2013.
- III Games, Beirut (Lebanon) 1959
- Reprinted and new edition of Hrvoje Kačić's U službi domovine
- Granting recognition
- Partisans killed Croatian anti-fascists, Hrvoje Kačić, Glas Koncila
- News in short, Croatian Radiotelevision
- Vijenac reviews
- Matija Ljubek Award
- Recipients of the Franjo Bučar State Award for Sport in 2002
- "Vaterpoliste dočekalo 30.000 ljudi" [Waterpolo players met by 30,000]. Nacional (in Croatian). 3 April 2007. Archived from the original on 30 June 2012. Retrieved 30 June 2012.