Ten anther-derived monoploids, twelve doubled monoploids and the heterozygous anther donor clone of Solanum phureja were compared for six vegetative, eight reproductive and three yield characters in the greenhouse. Significant high correlations were observed between the monoploids and their doubled monoploids for 14 of 17 characters. Therefore, doubled monoploids presumably express the same alleles as monoploids and the phenotypic expression of a monoploid can be used to predict accurately the phenotype of the derived doubled monoploid. Doubled monoploids flowered earlier and had significantly higher values than the monoploids for 15 of 17 characters, indicating a positive effect of increasing gene dosage from monoploid to diploid. Morphological traits can be used to distinguish plants of the two ploidy levels. Significant differences among clones were observed for all parameters within each ploidy level. The anther donor was not significantly different from the mean of doubled monoploids for 10 of 17 characters. For each of 14 characters, some doubled monoploids exceeded the anther donor. Therefore, doubled monoploids which do not express homozygote depression can be obtained.