Łukasz Kadziewicz was born in Dobre Miasto, Poland. He was married with Kamilla. On March 21, 2006 was born their daughter Amelia. They divorced in 2008. He married to Barbara (nee Gołąb).
When Łukasz were a member of Polish national team he created "Kadziu Project". He filmed videos that showed how Polish team was preparing for matches and how they lived during championships (for example Olympics in Beijing 2008). When Kadziewicz ended his career in the national team, his idea took Krzysztof Ignaczak, who continued this work under the name "Igłą Szyte". In 2013 Kadziewicz reactivated "Kadziu Project", but instead of showing life in national team, he makes interviews with volleyball players and talks about his thoughts related to volleyball.