The research results of growth regulators with anti-stress action which stimulated growth and development of plants, and achieving their resistance to adverse factors during vegetation period, have been presented. The use of plant growth regulators with anti–stress effect on Sinapis alba L. increased plant resistance to adverse environmental influences, providing adaptation to changing environmental conditions, i.e. has a stress–correcting 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%. The most effective over the years of research were applications of growth regulators Fast Start and Biofoge. The most effective processing terms were: during vegetation period and combination of seed treatment and application during vegetation period.