The aim of this research was to study the influence of lead acetate on spore germination and gametophyte differentiation in the pteridophyte species Athyrium filix-femina, Dryopteris affinis and Dryopteris carthusiana. The study was conducted to determine the lead tolerance level of these species.The experimental variants were: Control - Knop solution, V1-100 ppm lead acetate and V2-500 ppm lead acetate. The spores were cultivated in 50 ml of experimental solutions. The culture vessels were kept in the growth room in controlled conditions. The percentage of spore germination was determined after two weeks. Microscopic observations were performed on gametophyte development after 3, 7 and 15 weeks, respectively from the initiation of cultures. Lead acetate influenced both spore germination and gametophyte differentiation. As regards the germination process, Athyrium filix-femina was the least influenced by the lead acetate added to its culture medium. In addition to the decline in germination percentages, we also recorded a delay in the process of gametophyte differentiation and necrosis of prothallic cells. In the V2 variant we noticed the inhibition of cell division in the germinated spores; no further gametophyte differentiation occurred. Athyrium filix-femina is a more tolerant species to this substance as compared with Dryopteris affinis and Dryopteris carthusiana.