Combustible cigarette smoking is known to elevate hemoglobin (Hb) levels primarily through carbon monoxide mediated erythropoietic stimulation. In contrast, the hematologic effects of exclusive e-cigarette use remain poorly defined, especially in primary care settings where clinicians frequently counsel on tobacco and nicotine products.To compare Hb concentrations across four tobacco use patterns non-smoking, exclusive e-cigarette use, exclusive combustible cigarette smoking, and dual use and to determine whether exclusive e-cigarette use is associated with Hb elevation.This observational analysis used nationally representative data from adult men aged ≥19 years with complete information on smoking behavior and e-cigarette use. Participants were categorized into four mutually exclusive groups: non-smokers, exclusive e-cigarette users, exclusive combustible cigarette smokers, and dual users. Hemoglobin concentration was the primary outcome. Individuals without Hb data were excluded from regression analyses. Age-adjusted linear regression was used to evaluate Hb differences across groups, and predictive margins were estimated to obtain adjusted mean Hb levels.A total of 1,311 men met inclusion criteria, of whom 1,290 had available Hb measurements. Age-adjusted mean Hb levels were 15.31 g/dL in non-smokers, 15.19 g/dL in exclusive e-cigarette users, 15.54 g/dL in exclusive smokers, and 15.60 g/dL in dual users. Compared with non-smokers, exclusive combustible cigarette smokers (β = 0.23 g/dL, p < 0.001) and dual users (β = 0.29 g/dL, p = 0.001) showed significantly higher Hb levels. Exclusive e-cigarette use was not associated with Hb elevation (β = –0.12 g/dL, p = 0.39).These findings reinforce that Hb elevation reflects exposure to combustion-related toxicants rather than nicotine delivery. The absence of increased Hb among exclusive e-cigarette users suggests that non-combustible nicotine products do not trigger the compensatory erythropoietic response observed in combustible smoking.Conventional cigarette smoking was associated with increased hemoglobin levels, whereas e-cigarette use showed no such association. The type of tobacco product should therefore be considered when evaluating hemoglobin elevation and its underlying mechanisms in primary care practice.