Forced expiratory maneuvers are routinely used in children, 6 years of age and older for the diagnosis and follow-up of respiratory diseases. Our objective was to establish normative data for an extensive number of parameters measured during forced spirometry in healthy 3- to 5-year-old children. Children aged between 3 and 5 years were tested in 11 daycare centers. Usual parameters, including FEV1, FVC, PEF, FEF25-75, FEF25, FEF50, FEF75, and Aex were measured and analyzed in relation to sex, age, height, and weight. In addition, the same analysis was performed for FEV0.5 and FEV0.75. One hundred sixty-four children were recruited for testing including 87 girls and 77 boys. Thirty-five were 3 years old, 63 were 4 years old, and 66 were 5 years old. Overall, 143 children (87%) accepted to perform the test and 128 children (78%) were able to perform at least two technically acceptable expiratory maneuvers. Analyses using different regression models showed that height was the best predictor for every parameter. In conclusion, the present study confirms that most healthy 3-5 years old children can perform valid forced expiratory maneuvers. In agreement with other studies, we found that height is the most important single predictor of various parameters measured on forced spirometry. The present study is the first to establish normative values for FEV0.75, as well as to demonstrate that Aex can be easily performed in the majority of children aged 3-5 years. These are likely important parameters of lung function in this age range.