We conducted a systematic review of literature reporting on the prevalence of assessment measures, treatments, and biomarkers used in the diagnosis and treatment of posttraumatic stress disorder (PTSD) in Iraqi, Kurdish, and Syrian refugees. We performed a search of medical, psychological, and sociological databases on all relevant literature published between January 2011 and March 2016. Seventeen manuscripts met the study inclusion criteria. Seven assessment measures were used in more than 1 study, 4 of which were clinically administered (Vivo Checklist of War, Detention, and Torture; Clinically Administered PTSD Scale (CAPS); Mini International Neuropsychiatric Interview; and Hamilton Depression Rating Scale), and 3 of which were self-report measures (Harvard Trauma Questionnaire (HTQ); Hopkins Symptom Checklist-25 (HSCL-25); Post Migrational Living Difficulties (PMLD)). Two studies reported on psychological treatment, both of which administered Narrative Exposure Therapy (NET); no other systematic psychological treatments were identified. Several biomarkers were investigated but only in a single study each, including magnetic resonance imaging (MRI) of lateral prefrontal regions, right inferior parietal cortex, and bilateral isthmus of the cingulate, EEG event-related potentials, hypercortisolemia, and elevated heart rate. On the basis of these findings, we advocate the use of the HTQ, HSCL-25, and PMLD to exclude PTSD noncases and the CAPS for diagnosis of PTSD in Iraqi, Kurdish, and Syrian refugees in Canada. We further suggest NET as the psychological treatment currently with the strongest evidence base in this population. Finally, we advocate continued research into biomarkers as a means of improving and objectifying psychological assessment and treatment of PTSD in Canadian refugee populations.