On-farm cropping systems research involving banana (Musa sp.) dasheen (Colocasia esculenta) and cowpeas (Vigna unguiculata) was initiated on six sites with similar production environments and soil type (Aquic Tropudults) in Fond Assau, St. Lucia. The prevalent farmers' pattern (Control) was compared against experimental alternatives. The use of partial budgets and performance criteria such as returns above variable costs (RAVC) showed that the alternatives are 16-30% superior than that of the control. Alternative patterns indicated a marginal benefit-cost ratio (MBCR) varying from 2.4 to 4.7 as compared to the farmers' existing pattern. Yield, yield parameters, leaf characteristics and growth of banana at 7 months after planting were unaffected by the various treatments. However, the production cycle was extended to a maximum of 17 days in banana + 2 dasheen + 3 cowpeas. The cropping systems significantly reduced the weed growth.