Abstract: The objective of this research was to determine the profile, distribution and solasodine contents in the transformed plants compared to the control plants. Transgenic plants were regenerated spontaneously in vitro from Agrobacterium rhizogenes-transformed root cultures of Solanum nigrum L. (black nightshade). Upon transfer to greenhouse, all the transformed root-derived plants were fertile with seed set considerably reduced compared to the control plants. The seeds harvested from the mature plants were used to study the steroidal alkaloid solasodine productivity during 16 week of plant development in greenhouse. Chromatographic analyses (TLC and HPLC) and IR spectrophotometry analysis showed that the solasodine profile in the transformed plants was similar to the solasodine profile in control plants. Solasodine contents in plant parts of the transformed plants were lower compared to that of the control plants. The solasodine contents in the control plants were 9.93 mg g-1 (roots), 6.10 mg g-1 (stems), 4.06 mg g-1 (leaves) and 0.61 mg g-1 (fruits), whereas the solasodine contents in the transformed plants were 7.75 mg g-1 (roots), 2.12 mg g-1 (stems), 3.98 mg g-1 (leaves) and 0.71 mg g-1 (fruits). Solasodine was differently distributed in the transformed plants compared to the control plants. In control plants, the highest solasodine accumulation was occur in stems (78.1%), whereas in transformed plants the highest solasodine accumulation was occur in leaves (51.6%). It seems that the presence of rol (A, B, C and D) genes contained in the TL T-DNA is detrimental to the solasodine accumulation in the transformed plants in contrast to transformed root cultures.