Scots pine(Pinus sylvestrisL.) seeds were induced to germinate by a 15 min red light (R) treatment after a 5 h wet incubation in the dark. Controls, irradiated with 15 min R immediately followed by far‐red light (FR) for 5 min. were run in parallel. Cytokinins of the zeatin riboside type were quantified at the first, second and third day after the light treatment. The cytokinin determination was carried out with an enzyme‐linked immuno‐sorbent assay (ELISA) with polyclonal antibodies raised againsttrans‐zeatin riboside (ZR). Evidence for the occurrence of ZR in the extract was further established by high performance liquid chromatography (HPLC) of samples purified on immunoaffinity columns. The short pulse of R led to a transient increase in endogenous ZR‐type cytokinins on the second day whereas there was no marked change during the time course after FR treatment. It is suggested that the ZR‐type cytokinins were involved in the regulation of incipient growth activity taking place after the period of germination in astrict sense.