Nowadays, when the rational usage of agricultural production space is promoted, the pre-sowing seed treatment with physical factors becomes more important. These factors, which are generally considered as harmless for the environment, most often modify the course of some physiological and biochemical processes in the seeds, increasing their vigour and ensuring better plant development at later stages. The magnetic field is especially worth our attention, since its impact on the seeds can change the course of some processes taking place in the seeds and so stimulates plant development. However, this issue can also be significant in the cultivation of leguminous plants as this group is characterised by low yields which vary considerably from year to year. The present study was carried out in the Institute of Soil Science and Plant Cultivation in Puławy, in the years 2000-2002. The factor of the 1st order were two varieties of the pea seeds, ie: Rola - a leafy type, and Piast – an afila type; whereas the factor of the 2nd order – 3 exposure doses of magnetic field: D0 – without laser treatment (control), D1 – 10 750 J m-3 s (B = 30 mT, s = 15 s) and D2 – 85 987 J m-3 s (B = 85 mT, s = 15 s). Seed treatment was carried out in the Department of Physics of the University of Agriculture in Lublin. The study carried out proved a favourable influence of the magnetic treatment on the emergence, growth and development of both pea varieties. The pre-sowing treatment of the pea sowing material with a magnetic field resulted in a significant increase in the seed yield. The efficiency of the treatment applied depended on the variety, the exposure dose of the magnetic field and the course of weather conditions. The increase in the pea seed yield due to this treatment resulted from a higher number of pods per plant and lower losses of plants from a surface unit during vegetation.