Effects of composition variations of potassium thiocyanate and sodium thiosulfate as fixing agents in a P-Q monobath were investigated. Thiocyanate acts remarkably as an accelerator for development in the monobath especially at lower exposure levels. An addition of 40 mole % of thiocyanate per total fixing agentswhen the concentration is adjusted to obtain the required gamma, leads to the highest effective speed of photographic materials. Practical formulations for commercial negative films are considered.