Recently, more and more studies have shown that platelet count (PLT) may be associated with the prognosis of lung cancer (LC). However, the prognostic role of PLT in lung cancer is still controversial. In the present study, we conducted a meta-analysis of all available English studies to evaluate the prognostic value of PLT in lung cancer. In order to investigate the association between PLT and overall survival (OS), the hazard ratio (HR) and its 95% confidence interval (CI) was evaluated. The odds ratio (OR) with its 95% confidence interval (CI) was used to assess the relationship between PLT and clinicopathological parameters. There were 12 studies (n = 5,884) were involved in this meta-analysis. The pooled results showed that elevated PLT was a negative predictor for OS and the pooled HRs was significant at 1.74 (95% confidence interval, 1.39-2.19). Elevated PLT was also significantly associated with advanced TNM stage (OR: 2.65, 95% CI: 1.77-3.97) and smoking history (OR: 2.70, 95% CI: 1.79-4.08). In addition, there was no significant correlation between elevated PLT and squamous cell carcinoma (OR: 1.54, 95% CI: 0.7-73.07). Our results demonstrated that elevated PLT denotes a poor prognosis in patients with LC.