BACKGROUND: Macrocytosis is associated with an increased risk of squamous cell carcinoma (SCC) arising in the esophagus in men. The aim of this study was to evaluate the association between macrocytosis and metachronous SCC of the esophagus after endoscopic resection (ER) of early esophageal SCC in men. METHODS: The study group comprised 278 men with early esophageal SCC after ER. The main study variables were as follows: (1) cumulative incidence and total number of metachronous SCC of the esophagus according to the presence or absence of macrocytosis (mean corpuscular volume ≥ 106 fl) and (2) predictors of metachronous SCC of the esophagus as assessed with a multivariate Cox proportional-hazards model. RESULTS: The median follow-up was 50.3 months. Macrocytosis was associated with a higher 2-year cumulative incidence of metachronous SCC of the esophagus (without macrocytosis vs. with macrocytosis: 11.4% vs. 38.1%, p = 0.002). Macrocytosis was also associated with a higher total number of metachronous SCC of the esophagus per 100 person-years (without macrocytosis vs. with macrocytosis: 7.7 vs. 31.5 per 100 person-years, p < 0.0001). In addition, macrocytosis was a significant predictor of metachronous SCC of the esophagus on multivariate Cox proportional-hazards analysis (relative risk 2.23). CONCLUSION: Macrocytosis is a useful predictor of the risk of metachronous SCC of the esophagus after ER of early esophageal SCC in men.