Obstructive sleep apnea (OSA) is accompanied by significant daytime cognitive and behavioral deficits that extend beyond the effects of sleepiness. This article outlines a causal model by which to understand these psychological effects among OSA patients. The model proposes that sleep disruption and blood gas abnormalities prevent sleep-related restorative processes, and further induce chemical and structural central nervous system cellular injury. This, in turn, leads to dysfunction of prefrontal regions of the brain cortex (PFC), manifested behaviorally in what neuropsychologists have termed 'executive dysfunction'. Executive dysfunction is proposed to markedly affect the functional application of cognitive abilities, resulting in maladaptive daytime behaviors. The proposed model (1) accounts for the specific psychological phenotype associated with OSA, (2) accommodates developmental components in this phenotype, (3) bridges between physical and psychological phenomena, (4) suggests mechanisms by which the nocturnal disorder might have effects on daytime functioning, (5) is empirically testable, (6) generates unique research hypotheses, and (7) has practical implications. The model is intended to act as a catalyst for future research and as a preliminary guide for clinicians.