3H-alpha-Chaconine was poorly absorbed from the gastrointestinal tract and rapidly excreted in feces when administered orally to male rats. Intraperitoneal administration of low doses (5 to 10 mg/kg) resulted in urinary and fecal excretion of metabolites, and probably involved biliary excretion. High, toxic, intraperitoneal doses (15 to 25 mg/kg) depressed fecal and urinary elimination, and resulted in accumulation of tritium in various tissues. The major metabolite appeared to be the aglycone, solanidine. Alpha-chaconine is very similar to alpha-solanine in its elimination by and distribution in tissues of rats.