As in most mass-market photography magazines, much of the editorial content of Camera Mainichi was devoted to news and reviews of cameras, lenses, and other equipment. But from the start it found space for first-rate and unconventional photography, and especially during the period 1963–78 when it was edited by Shōji Yamagishi it seemed more adventurous than its major rivals Asahi Camera and Nippon Camera (which both survived it). After Yamagishi left, it devoted more space to fashion and mildly erotic photography.
The magazine also published the results of two photo contests sponsored by Mainichi Shinbun-sha: the Mainichi photography award (1955–58) and the Domon Ken Award (from 1982).
Although mainichi literally means "daily", the magazine was instead named after its publisher, Mainichi Shinbun-sha (best known for its daily newspaper Mainichi Shinbun).