The study reported here looked at adverse health effects associated with pesticide exposure among cut-flower farmers in La Trinidad, Philippines. Survey questionnaires and detailed physical and laboratory examinations were administered to 114 and 102 respondents, respectively, to determine pesticide exposure, work and safety practices, individual and family illnesses, and cholinesterase levels. Results showed that pesticide application was the activity most frequently associated with pesticide exposure, and entry was mostly ocular and dermal. Involvement of the skin was noted, with 21 percent of farmers having integumentary abnormalities. Upon physical examination, 90 respondents, or 88.2 percent of those examined, were found to have abnormal peak expiratory flow rate (PEFR). Abnormal temperature was found in 81.3 percent, and the next most frequent finding was abnormal general-survey results, at 75.5 percent. In 51 percent, cholinesterase levels were below the mean value of 0.7 delta pH/hour. (The unit of measure A pH/hour refers to the change in cholinesterase activity as measured by the difference between the initial pH and the final pH when acetylcholine solution has been added to the red blood cell for 1 1/2 hours. A decrease in cholinesterase activity will produce a low delta pH/hour level) In 25.5 percent, a more than 10 percent depression in the level of RBC cholinesterase was found. Certain hematological parameters were also abnormal, namely hemoglobin, hematocrit, and eosinophil count. Using Pearson's r, the author found that factors strongly associated with illness due to pesticides include use of a contaminated piece of fabric to wipe off sweat (p = .01) and reuse of pesticide containers to store water (p = .01), Recycling of containers poses great health hazards and risks of contamination, and the current recommendation is that used containers should be buried. There was a moderate relationship between illness and average number of years of pesticide use (p = .05), and between illness and re-entering a recently sprayed area (p = .05). Those with motor scale scores of < or = 15--normal values--were less likely to be sick. The greatest adverse effect in those exposed was an abnormal cholinesterase level, a finding that confirms results from earlier studies on the effect of pesticides on the body.