Burns can be a traumatic and stressful experience, although each patient may respond in very different ways. The aim of this study was to explore the variability on posttraumatic stress disorder (PTSD) and acute stress disorder (ASD) prevalence and evaluate the specific weight of different variables on PTSD development among adult burn patients. A systematic review was carried out to explore the prevalence of ASD and PTSD and identify their predictors. Meta-analytical methods were used to explore the strength of association between PTSD and the latter. From an initial pool of 190 studies, 24 were used in the systematic review, and only 19 studies could be used for the meta-analysis because of different methodological limitations. The prevalence of ASD at baseline ranged from 2 to 30% and prevalence of PTSD ranged from 3 to 35% at 1 month, 2 to 40% between 3 and 6 months, 9 to 45% in the year postinjury and ranged 7 to 25% more than 2 years later. Life threat perception was the strongest predictor for PTSD occurrence, followed by acute intrusive symptoms and pain associated with burn injuries. Predictive variables identified in this research may be useful in targeting burn patients who are at risk for developing posttraumatic stress symptoms and stress-related psychological symptoms.