Pesticides may contribute to adverse respiratory health effects among farmers and have been considered one causal factor for the rise in asthma prevalence. This cross-sectional study was conducted to evaluate potential respiratory function abnormalities following long-term pesticide exposure by means of a complete pulmonary function testing, including spirometry, lung volumes, and diffusing capacity for carbon monoxide. The study population was comprised by workers from a prominent intensive agriculture area of southern Spain that relied on pesticides for the control of plagues. Eighty-nine pesticide sprayers of plastic greenhouse farming and a control group of 25 nonspraying control farmers from the same area were interviewed by a general practitioner asking about sociodemographic factors, occupational exposure, and clinical symptoms by using a structured questionnaire. Multiple regression analyses showed a relationship of short-term exposure to pesticides (as indicated by a drop in serum cholinesterase > 25% of baseline levels) with reduced forced expired volume in 1 s, and of long-term exposure (as indicated by a cumulative pesticide exposure index) with reduced forced expiratory flow rate. Exposure to bipyridilium-class herbicides was a determinant of a fall in the diffusing capacity of the lungs, and neonicotinoid insecticides showed a relationship with lower pulmonary volumes (total lung capacity, residual volume, and functional residual capacity), suggestive of restrictive lung disease, and with an increased risk of reporting irritative symptoms.