Alpha and beta carotene, provitamin A activity, dehydroascorbic acid, L-ascorbic acid and total ascorbic acid content of ' 'jalapeho," 'bell," long green/red "chile," " serrano" and "yellow wax" peppers (Cupsicutn unnuum L.) at green and red stages of maturity were determined by HPLC. Effects of thermal processing on vitamin A and C retention in "jalapeno" peppers was also determined. Provitamin A activity ranged from 27.3 to 501.9 Retinol Equivalents (RE/loOg). Ascorbic acid concentration ranged from 76.1 to 243.1 (mg/lOOg). Provitamin A activity and ascorbic acid content increased with maturity in all cultivars. Thermal processing of "jalapeho" cultivars resulted in a 25% decrease of total provitamin A activity and a 75% decrease in total ascrobic acid.