Cyclometalated Pt II complexes have drawn a lot of interest because they show interesting photoluminescence properties with potential applications in optical materials such as OLEDs and WOLEDs. Recently, heteropolymetallic cycloplatinated complexes have also been identified as systems of interest because they readily allow emission tuning by suitable choice of heterometal, cyclometalated groups and coligands. This review describes the synthetic routes, structural aspects and photoluminescence properties of heteropolynuclear complexes containing cycloplatinated fragments. In turn, cycloplatinated complexes have also been investigated as molecular sensors of ions via photoluminescence responses.