Insomnia is a highly prevalent condition, affecting up to 30% of adults. Research has shown that insomnia may be an independent predictor of heart disease, which is the second leading cause of death in Canada. Heart rate variability (HRV) is a proxy of autonomic activity often used to estimate current heart health. The present study investigated whether sleep disturbance and psychological variables were independently associated with HRV in a highly characterized (n = 140) sample of people with insomnia. Whereas sleep disturbance as assessed by polysomnogram was not found to predict HRV, worry was associated with HRV in rapid eye movement sleep. Results suggest that sleep does not relate to HRV; rather, worry may be important to HRV, though the nature of this association remains unclear. Previous studies showing that sleep and HRV are related may have been due to inadequate assessment of comorbid psychiatric symptoms.