Background and Objective: Dorema aucheri, Stachys pilifera and Trachyspermum copticum are used in Iranian traditional medicine especially in the province of Kohgilouyeh and Boyerahmad. This study aimed to determine the effect of these plants on proliferation of rat brain oligodendrocytes. Materials and Methods: Macerated hydroalcoholic extract of each plant was prepared using 50% ethanol. The OLN-93 oligodendrocytes were incubated for 24 h with different concentrations of these extracts. Then, percentage of viable cells was determined using a method based on the reduction of tetrazolium salt. Results: Extract of Dorema aucheri at 50, 100, 200, and 400 µg/ml decreased viable cells from 100 ± 4% (control cells) to 84 ± 4, 58 ± 6 (P<0.001), 6 ± 0.5 (P<0.001), 4 ± 0.5% (P<0.001), respectively. Similarly, Stachys pilifera extract at 50, 100, 200 and 400 µg/ml decreased viable cells from 100 ± 4% to 81 ± 6, 64 ± 3 (P<0.01), 61 ± 4 (P<0.01), 55 ± 2% (P<0.001), respectively. Also, Trachyspermum copticum extract at concentrations higher than 50 µg/ml significantly decreased percentage of viable cells. Conclusion: Extracts of Dorema aucheri, Trachyspermum copticum and Stachys pilifera reduce proliferation of rat brain oligodendrocytes.