According to the prefrontal model, individuals with obstructive sleep apnea (OSA) manifest behaviours mimicking dysexecutive syndrome as a result of blood gas abnormalities and sleep fragmentation. To compare executive functions in OSA patients with normative values and explore their relationship with blood gas abnormalities and sleep fragmentation. Patients were recruited from the wider community and from a tertiary care hospital. The score obtained in the neuropsychological assessment was compared with Student's t-test for a sample. A multiple linear regression analysis was subsequently estimated, using polysomnographic parameters of hypercapnia, hypoxemia and sleep fragmentation as the predictor variables, and the executive function score as the variable to be predicted. Although the neuropsychological assessment performance of 26% of this sample was classified as executive impairment, indicators of sleep fragmentation and gas abnormalities failed to predict the performance of executive functions. A proportion of the patients with OSA presented performance similar to a dysexecutive syndrome; however, the factors underlying and fostering this type of cognitive manifestation remain unclear. Early treatment for this public health problem could be the best tool available for improving quality of life and preventing health risks.