Tamarillo (Solanum betaceum Cav.) also known as tree tomato, is an exotic fruit from the Andes region with growing cultivation in Latin America. In Brazil, this fruit is considered a non-conventional edible plant (PANC) with high food and nutritional potential, but it is not consumed on a large scale. The antioxidants compounds are believed to partially contribute to health-promoting effects of tamarillo, including antioxidation and antioxidative stress, anti-obesity, anticancer and anti-microbial activity. The aim of this study is to evaluate antioxidant activity of two bioactive tamarillo extracts in vitro and antiproliferative effects in cells lines. The extracts were prepared from tamarillo fruits in natura, using ethanol:water (80:20) and water as solvents at ultrasonic bath. The evaluation of antioxidant activity was performed using the DPPH and ORAC assays and antiproliferative effects DU145 prostate cancer cells was available for MTT assay. DPPH and ORAC methods showed higher antioxidant activity (p<0.05) in ethanol extract (EE) (514.90 ± 49.02 molTE/g and 2715 ± 592.7 molTE/g, respectively) than aqueous extract (EA) (340.07 ±2 9.88 molTE/g and 1948 ± 493.1 molTE/g, respectively). It suggests that majority compounds associated with tamarillo antioxidants have higher affinity and superior extraction by organic solvents, as in the case of the ethanol extract. EA (34,66%) and EE (45,73%) reduced DU-145 cell viability at high concentrations (5000µg/mL), after 48h treatment. The results are part of a larger study which provides information about the benefits of bioactive compounds and suggests that tamarillo extracts as a potent antioxidant and antiproliferative in human prostate cancer cells.