Farm workers in developing countries tend not to use protective measures while handling pesticides. This study investigates the use of personal protection equipment and the practice of safety and hygiene procedures in the handling of pesticides in agriculture. Through a multi-stage sampling technique, one-fifth of the farms in a region were selected and all the farm workers at these farms were included in the study. A comparison population matching in age, socio-economic status and stay in the region was selected. A specifically designed questionnaire was used to collect information on the use of protective measures and the practice of safety and hygiene during work and on the disposal of empty pesticide containers. Blood pressure and erythrocyte acetylcholinesterase (AChE) activity were measured in the exposed and the unexposed populations. Protective equipment was worn by a minority of farm workers - gloves, by 35%; work coveralls, by 36%; a scarf to cover the nose and mouth, by 39%; and shoes at work, by 79%. With regard to personal hygiene measures, 83% of the workers changed clothes after work and the same proportion took a shower after work; 63% and 46% drank and ate while at work respectively; and 11% used articles of domestic use in the preparation of pesticides on the farm. Most of the farm workers (96%) were asked to prepare pesticides for spraying by the foreman and 61% were asked to spray the pesticides on the crops. AChE activity was highly significantly depleted in the exposed population as compared with the unexposed population. AChE depletion was found to be negatively associated with the use of gloves, of work coveralls, and of a scarf to cover the nose and mouth and with the implementation of safety and hygiene procedures on the farm. AChE depletion was positively associated with the frequency of pesticide spraying.