Our aim was to evaluate the prognostic role of the pretreatment serum albumin level in patients with malignant pleural mesothelioma (MPM) receiving platinum-based systemic chemotherapy. From 1995 to 2013, a total of 97 patients receiving platinum-based systemic chemotherapy for newly diagnosed MPM were enrolled. All clinical information and laboratory results were retrospectively collected from the medical records. The Kaplan-Meier method was used to calculate survival. The Cox proportional hazards model was used to identify significant independent prognostic factors for predicting survival. In total, 34 of the 97 patients (35.1 %) had hypoalbuminaemia (albumin ≤ 35 g/l). The 1-year overall survival rate was 44.1 % for patients with hypoalbuminaemia and 72.0 % for patients with a normal albumin level. Multivariate analysis indicated that pretreatment albumin was an independent prognostic factor in MPM. Patients with hypoalbuminaemia had a greater risk of death than those with a normal albumin level [hazard ratio (HR) 1.778; 95 % confidence interval (CI) 1.504-2.998; P = 0.031]. When albumin was entered as a continuous variable in the Cox regression model, the HR of death was significantly decreased by 9.8 % (95 % CI 0.851-0.956) for each 1-g/l increment. The pretreatment serum albumin level is a simple, inexpensive and easily measurable marker with prognostic significance in MPM patients treated with platinum-based systemic chemotherapy.