Yogurt is a fermented dairy product, manufactured by starter culture and consumed widely around the world. It may become contaminated with aflatoxin M1 (AFM1) that causes threats to the health of consumers, especially young children and adults. There are different methods to detoxify foods from AFM1, but in yogurt, the easiest way is biodetoxification method using different cultures and probiotic agents. So the aim of this study was to evaluate the effect of starter culture and Lactobacillus casei in detoxification ofAFM1. For this purpose skim milk powder was contaminated artificially withAFM1 at levels: 0.05, 0.1, 0.5, and 0.75 ppb.Yogurt samples including control (inoculation just by started culture-YC280) and treatments (inoculation by starter culture and Lb.casei- 431) fermented at 42°C to reach pH<4.6 and consequently the AFM1 content was measured by ELISA technique. Results showed that in the control samples and treatments, the toxin was removed 94.35 and 94.15 respectively. There was no significant difference between control and the treatment.