Vegetative and basidiospore inocula of Pisolithus tinctorius were artificially introduced into soils of three nurseries in Georgia, Florida, and North Carolina. After one growing season in the North Carolina nursery, growth stimulation by Pisolithus ectomycorrhizae from vegetative inoculum was 140 percent on seedlings of Pinus taeda and approximately 100 percent on seedlings of P. virginiana and P. strobus. Vegetative inoculum of Pisolithus formed 97, 94, and 77 percent of the ectomycorrhizae on P. taeda, P. virginiana, and P. strobus, respectively. Ectomycorrhizae formed from basidiospore inoculum did not dominate the root systems or stimulate seedling growth as much as vegetative inoculum. In the Florida nursery, Pisolithus ectomycorrhizae produced by both types of inocula were in approximately even mixtures with ectomycorrhizae formed by naturally occurring fungi. Growth stimulation by P. tinctorius ectomycorrhizae was not observed on seedlings of P. taeda, P. elliottii var. elliottii, or P. clausa in this nursery. Ectomycorrhizal development by P. tinctorius on P. taeda, P. virginiana, and P. clausa did not occur in the Georgia nursery, probably due to ineffective soil fumigation. Plant-parasitic nematodes and high populations of Pythium irregulare-P. debaryanum were isolated from plots in this nursery. The practical significance of lateral spread of Pisolithus into noninfested soil adjacent to infested soil and basidiocarp production is discussed. These results show that P. tinctorius can be artificially introduced into fumigated soil and form specific ectomycorrhizae on various pine species under diverse cultural conditions used in conventional nursery production of pine seedlings. Forest Sci. 22:91-100.