Sleep disturbance is a core feature of post-traumatic stress disorder (PTSD). Given the relationship between sleep disturbance and PTSD, there has been a relative paucity of studies examining the potential therapeutic impact of using pharmacotherapy to target sleep disturbance in patients with PTSD. Eszopiclone (ESZ) is a non-benzodiazepine y-aminobutyric acid-A receptor agonist indicated for the treatment of sleep and may affect sleep in patients with PTSD. To evaluate the efficacy of ESZ vs placebo (PBO) for patients with PTSD and insomnia. The study was a 12-wk, double blind, randomized controlled trial with 3 mg of ESZ (n = 13) or PBO (n = 12). Patients in both arms experienced significant improvement in PTSD symptoms as assessed by the Clinician-Administered PTSD Scale for DSM-IV (CAPS): ESZ (t11 = -3.12, P = 0.005) and PBO (t11 = -3.5, P = 0.002) and by self-report with the Short PTSD Rating Interview (ESZ t11 = -3.38, P = 0.003 and PBO t11 = -4.48, P = 0.0005). There were no significant differences between treatments on the CAPS (t22 = -0.13, P = 0.70) or the Short PTSD Rating Interview (t22 = -0.58, P = 0.56). Similarly, both treated groups improved on sleep measures as assessed by the Pittsburgh Sleep Quality Index with PTSD Addendum (PSQI) and on total sleep time (TST) and sleep latency assessed by actigraphy with no significant differences between groups (PSQI t22 = -0.24, P = 0.81; total sleep time t10 = 0.13, P = 0.90 and sleep latency t10 = 0.68, P = 0.50). There was a significant correlation between improvement in sleep and overall improvement in PTSD as measured by change scores on the PSQI and CAPS, r(8) = 0.79, P = 0.01 for ESZ treated subjects, but not for those treated with PBO r(9) = 0.16, P = 0.69. Adverse events of ESZ were consistent with the known profile of the medication including dysgeusia (30%, mild), sedation (20%, mild) and headache (20%, moderate to severe). Results do not support the hypothesis of a specific positive effect of ESZ compared to PBO for measures of PTSD and associated sleep disturbance. ©The Author(s) 2020. Published by Baishideng Publishing Group Inc. All rights reserved.