One of the main criteria of probiotics is their safety. The purpose of present research was to evaluate the safety of Lactobacillus rhamnosus (ATCC: 7469) in male Wistar rats. A subacute 28-day toxicity study was conducted. Two groups of male rats (n=6/group) were used. Control group received saline and the experimental group received 1 × 109 CFU/rat of L. rhamnosus (ATCC: 7469) for 28 consecutive days. Analysis of weigh changes, general observations, hematological factor, and serum parameters showed no toxicity of the bacterium in male Wistar rats.