BACKGROUND The association between platelet distribution width (PDW) and cancer has been evaluated by a few studies, but the influence of PDW on cancer prognosis is unclear. Therefore, we conducted the present meta-analysis. MATERIAL AND METHODS We identified relevant research using identical search strategies. The influence of PDW level on cancer prognosis, as well as clinical characteristics, was analyzed. RESULTS A total of 11 studies comprising 2625 cancer patients were included in our meta-analysis. The results suggested that high PDW level was obviously related to poor OS (HR=1.54, 95%CI 1.18-2.00), especially for breast cancer (HR=1.21, 95%CI 1.07-1.36) and pharyngolaryngeal cancer (HR=3.06, 95%CI 1.68-5.57). Furthermore, high PDW was obviously related to poor OS both in older and younger subgroups, with combined HR estimates of 1.58 (95%CI 1.15-2.16) and 1.64 (95%CI 1.19-2.26), respectively. High PDW level was notably related to poor OS in the cut-off value ³16% subgroup (HR=1.84, 95%CI 1.01-3.40). Moreover, high PDW level was obviously associated with lymph node metastasis (OR=1.43, 95%CI 1.04-1.99). CONCLUSIONS The findings of this study suggest that PDW is an effective and convenient indicator of cancer prognosis. Furthermore, high PDW level is obviously associated with lymph node metastasis.