Epidemiological data on the chronicity of posttraumatic stress disorder (PTSD) symptoms in relation to trauma type and underlying pathways are rare. The current study explored how PTSD symptoms change over time across different trauma types and examined mediators of their persistence. A trauma-exposed community sample, whereof approximately one quarter met diagnostic criteria for PTSD, provided retrospective data on the duration of PTSD symptoms. Those who remitted and those who had not at the time of assessment were compared regarding worst trauma, symptom severity, comorbidity, demographic and treatment-seeking variables. Time to remission was estimated using Cox proportional hazard models including candidate predictors of remission. A mediated survival analysis was used to explore indirect pathways that explain trauma-specific differences in remission times. Both the full sample and PTSD subgroup were analyzed separately. Overall, lower socio-economic status, lifetime and childhood sexual trauma, symptom severity, comorbid depression and past treatment were associated with non- and longer remissions. PTSD avoidance symptoms and comorbid depression were found to mediate longer remission times after lifetime or childhood sexual trauma. Our findings provide insight into the mechanisms and complicating factors of remission from PTSD symptoms after trauma, which might have important implications for therapeutic interventions.