Abstract: Two trials were conducted in Costa Rica in the spring of 2007. One trial was conducted in a cantaloupe processing facility and the other in a facility that processes Spanish melons (piel de sapo). In both trials, the freshly harvested fruits were subjected to a variety of post-harvest treatments in an effort to improve the microbial condition of the fruit. In the cantaloupe trial, there were five different treatments, including fruit from the field, fruit from the field plus a 5 sec dip in 0.5% cetylpyridinium chloride (CPC), fruits that were washed commercially in 100 to 150 ppm total chlorine followed by a water rinse, washed fruits followed by a water rinse plus a 5 sec dip in 0.5% CPC and washed fruits followed by a water rinse plus a commercial fungicide. In the Spanish melon facility, there were four treatments, including fruits from the field, fruits from the field plus a 5 sec dip in 0.5% CPC, fruits that were washed in 100 to 150 ppm total chlorine (plus application of fungicide to the peduncle) and fruits that were washed in chlorine plus a 5 sec dip in 0.5% CPC. In addition, shelf-life studies at the appropriate temperatures were also conducted on both fruits; however, only the cantaloupes were subjected to a detailed sensory evaluation at the end of the shelf-life period. For field cantaloupes, the results indicate that a 5 sec dip in 0.5% CPC will allow for a 99% reduction in APC, no recovery of total coliforms and a 99.9% reduction in yeasts and molds. For Spanish melons from the field, a 5 sec dip in 0.5% CPC resulted in greater than a 90% reduction in APC and a 99% reduction in total coliforms and yeasts and molds. The commercial washing procedure in 100 to 150 ppm total chlorine followed by a water rinse (with or without the application of a commercial fungicide) was not very effective for reducing the levels of any of the groups of organisms in the cantaloupe facility. In fact, total coliforms remained unaffected by the commercial wash process. In the Spanish melon facility, the commercial wash procedure plus application of a commercial fungicide to the peduncle reduced APC by greater than 99% and total coliforms and yeasts and molds by greater than 90%. In comparison, the commercial washing process plus a 5 sec dip in 0.5% CPC resulted in the greatest reductions with almost complete elimination of APC, total coliforms and yeasts and molds from the cantaloupe and Spanish melons. The results from these trials suggest that the use of a CPC rinse solution as a treatment following commercial washing can significantly improve the overall microbial condition of fresh cantaloupe and Spanish melons. In addition, the sensory quality of cantaloupes at the end of refrigerated and retail storage was significantly improved when the fruit was subjected to a CPC-solution treatment following the commercial washing process.