The secondary embryogenic potential of Brassica napus L. ssp. oleifera (Metzg.) Sink. ev. Primor could be maintained for many years on complete Murashige and Skoog's medium without diminution. Experiments were conducted to investigate the effects of reducing or deleting certain components of the medium on secondary embryogenesis. Secondary embryogenesis was found to be significantly suppressed when strength of iron in the medium was reduced. Secondary embryogenesis, completely suppressed in ‘iron-free’ medium, could be regained when iron was incorporated into the medium. Micronutrients and organic nutrients in the medium had no effect on secondary embryogenesis. A reduction in the strength of the medium or its macronutrients decreased secondary embryogenesis significantly.