On the basis of 10-day and monthly measurements of atmospheric precipitation carried out in 56 meteorological stations of the Institute of Meteorology and Water Management (IMGW) during the period from 1965 to 2002, the time and spatial distribution of precipitation during the vegetation of early, medium early and late varieties of potato was characterized and the probability of the occurrence of optimum precipitation in relation to the earliness group and the soil category was defined. Average totals of atmospheric precipitation were advantageous for potato cultivation in all the examined soils in the southern part of Poland except for the cultivation of late potato in a heavy soil for which the precipitation conditions were more advantageous in the central part of Poland. The average area of Poland with optimum precipitation in the period of vegetation of late potato covers 25%, i.e. almost three times as much as the area with optimum precipitation for the early potato. The lowest average area of Poland with the most beneficial precipitation as well as the lowest probability of occurrence of the years with optimum precipitation in the period of vegetation were observed in a light soil. The optimum precipitation occurring during the period of potato vegetation in all the examined soils was observed most often (because the probability amounted to 20-30%) in the south of Poland except for the late potato in a heavy soil.