The research results of using growth regulators with anti-stress action which stimulated growth and development of plants, and provided them with resistance to adverse factors during the vegetation period, were presented. The use of plant growth regulators with anti-stress effect on Sinapis alba L. increased the plant resistance to adverse environmental influences, providing adaptation to changing environmental conditions, i.e. it has a stresscorrecting effect throughout the whole vegetation period. The result of using drugs on mustard (Sinapis alba L.) was obtaining a significant and stable additional seed yield (0.57 t•ha -1 ), i.e. an increase in yield by 38%. Over the years of research, the most effective were the applications of Fast Start and Biofoge growth regulators. The most effective processing terms were: during the vegetation period as well as combination of seed treatment and application during the vegetation period.