The semi-automated erythrocyte cellular antioxidant activity (ERYCA) method and Hydrophilic Oxygen Radical Absorbance Capacity (H-ORAC) assay were used to assess the ability of aqueous acetone extracts from 34 common tropical fruits to delay hemolysis of human erythrocytes and loss of fluorescein fluorescence respectively, when exposed to free peroxyl radicals induced by 2,2'-azobis (2-amidinopropane hydrochloride) (AAPH). The ERYCA assay quantifies both direct scavenging of free radicals and cell-mediated antioxidant protection (Cell-MAP). Because the H-ORAC method only analyzes the direct scavenging of free radicals in the reaction medium, Cell-MAP was deduced from the results of both assays. The results showed that Cell-MAP of fruit extracts on erythrocytes is, on average 3 to 4 times more than protection from direct scavenging of free radicals in the surrounding medium. The Cell-MAP of fruit extracts ranged from 0 to almost 4500 ?mol quercetin equivalents (QE) per 100 g on fresh weight basis, with tropical highland berries, cashew apple, mamey and 3 guavas species scoring the highest. Correlation coefficients among ERYCA, H-ORAC, Cell-MAP and total polyphenolic (TPP) content (assessed using a modified method excluding non-phenolics interference) were very high (r2>0.88 for all correlations), even though numerous discrepancies existed between the results of different methods. The analysis of Cell-MAP sheds new light on antioxidant rich food.