[1] [2] He won a gold medal at the 2015 European Athletics U23 Championships shot put event, with a throw of 19.35 m (63 ft 6 in).

[3] He won a silver medal at the 2013 European Athletics Junior Championships shot put event, with a throw of 20.23 m (66 ft 4 in).

[4] On 23 January 2016 Mihaljević won the shot put competition at Rod McCravy Memorial in Lexington, Kentucky with 20.69 m and thus qualified to the 2016 Olympic Games in Rio de Janeiro.

On 18 March 2016, competing at his very first senior world championships, in Portland, Mihaljević won the bronze medal in shot put competition with 20.87 m, his personal best.

In 2017, Filip become one of the few throwers who managed to capture both NCAA Outdoor Shot Put and Discus titles with impressive 21.30m and 63.76m respectively.