Experiments conducted over 5 years evaluated the effect of compost applications on the yield of several vegetable crops grown under organic farming conditions in the tropics. The yield of organically grown lettuce, basil, Filipino spinach (Corchorus olitorius L.), and zucchini after application of 20 MT compost/ha per crop was compared to yields obtained with standard synthetic fertilizer applications (150 kg N/ha per crop), and with a combination of several compost: synthetic fertilizer ratios. Treatments consisted of 10 by 1.30-meter raised beds replicated four times. Data collected included soil nutrient analysis prior to planting and after the last harvest, tissue analysis of macro- and micronutrients, canopy dimensions, and yields. The tissue nutrient levels collected from crops receiving composts alone were at or above those levels recommended to achieve commercially acceptable yields. Yields of plants receiving composts alone were comparable to those obtained by plants receiving synthetic fertilizer applications. However, the greatest yields were obtained with 20 MT·ha–1 of compost plus supplemental synthetic N applications, depending on the length of the harvesting period. After 5 years cumulative yields ranged from 110 to 124 MT·ha–1 for vegetables receiving compost plus supplemental N, compared to 75 for controls, and to about 100 MT·ha–1 for treatments receiving either synthetic N or compost applications alone.