Levels of gene flow, Nm, were calculated for 34 predominantly self-pollinated plants, using information on differentiation among populations, Gst.  Gene flow levels varied from 0.01 to 6.55, and departed significantly from a uniform distribution.  High, medium and low levels of gene flow were found among 15, 38, and 47 percent of the species, respectively.  The average heterozygosity (H)  and the Nm values showed a positively significant association.  These results were compared to gene flow levels obtained with a limited number of predominantly outcrossed plants.  Gene flow levels in several self-pollinated species were comparable to those characteristic of some outcrossed species.  Pollen flow, combined with long distance dispersal of propagules through various vectors may be responsible for the high levels of gene flow observed in self-pollinated species.  High gene flow may provide the genetic flexibility required for successful colonization, which is an essential feature of self-pollinated plants.