Acute poisoning among pesticide applicators is still a prominent health hazard in rural areas in developing countries, but published reports are very rare. Registration analysis and descriptive study are helpful in giving guidance for orientation and evaluation of preventive strategies and measures. Data and material from China show that, in circumstances with a well organized grass-roots-level network of primary health care services, poisoning episodes can be prevented through dissemination of information of hazards and provision of prevention training courses. Among pesticide manufacturing workers, especially manual packers of organophosphorus insecticides, there is suggestive evidence of subacute posioning resulting from continuous low-level exposure. Chronic delayed neuropathy has, rarely, been reported. Further study of the cause of subacute poisoning now requires analytical rather than descriptive investigations. There is still no solid documentation of an association of excess human cancer and the use of chlorinated hydrocarbon insecticides. Phenoxyacetic and chlorophenol herbicides recently have been widely studied for causation of soft tissue sarcoma, non-Hodgkin's leukemia, and lymphoma. Although the evidence at present indicates a positive association, discrepancies in findings and resultant controversy require further study. Epidemiological surveys on the harmful effect of DBCP are quite instructive. Investigations in exposed populations verified and extended the observation in animals as infertility and gender ratio change in the next generation. Adverse reproductive effects of a number of pesticides, particularly birth defects resulting from pesticides (other than those already documented for organomercurials), require further study.