This article describes novel optical functionalities such as photomagnetic effects and magnetization-induced second harmonic generation (MSHG) in several cyano-bridged metal assemblies. Single crystal- and film-types of a cyano-bridged Cu–Mo bimetallic assembly, $$ {\text{Cs}}^{{\text{I}}}_{{\text{2}}} {\text{Cu}}^{{{\text{II}}}}_{{\text{7}}} {\left[ {{\text{Mo}}^{{{\text{IV}}}} {\left( {{\text{CN}}} \right)}_{{\text{8}}} } \right]}_{{\text{4}}} \cdot {\text{6H}}_{{\text{2}}} {\text{O}} $$ , were electrochemically prepared. When this compound was irradiated with light, spontaneous magnetization with a Curie temperature (T C) of 23 K was observed. Electrochemically prepared FeII[CrIII(CN)6]2/3·5H2O thin film, which was a ferromagnet with T C=21 K, showed photoreduced magnetization. This photomagnetism is due to the change of ferromagnetic coupling between FeII and CrIII. MSHG was observed in CsICoII[CrIII(CN)6]·0.5H2O. This $$ F{\text{\ifmmode\expandafter\bar\else\expandafter\=\fi{4}3}}m $$ -type Prussian blue analog-based magnet is proven to be a piezoelectric ferromagnet, i.e., condensed matter with both piezoelectric and ferromagnetism. This MSHG is due to the coupling between a piezoelectric structure of $$ F{\text{\ifmmode\expandafter\bar\else\expandafter\=\fi{4}3}}m $$ and ferromagnetism with a T C of 46 K.