Textured growth of Co-Fe-Ga (CFG) alloy films by co-precipitation, low-temperature heat treatment (LTHT) at 333 K for 3 days, spin-coating, and post-annealing at 973 K for 30 min has been investigated. The X-ray diffraction measurements show that the CFG films made with LTHT are highly (110)-oriented bcc alloys, while those grown without LTHT are not oriented in a specific direction. The observed texture formation in the bcc alloy films results from topotactic transformation as indicated by the similarity of the ionic and atomic arrangements among the precursor, spinel oxide, and bcc alloy. The stabilization of the precursor by Ga3+ inclusion presumably plays an important role in the transformation process leading to the highly orientated spinel and CFG bcc alloy films.