The levels of reduced glutathione (GSH) were measured in the red blood cells of 259 cattle of two diverse populations consisting of various breeds. 2. There was a uniform distribution of GSH values ranging from 40.0 to 113.0 mg/100 ml red cells with a mean value of 72.0 mg +/- 1.26 (S.E.). 3. An absence of bimodal distribution was, thus, shown in the cattle breeds examined.