BACKGROUND: Carbon monoxide (CO) is air pollutants that have continued to increase in level. It might affect the body through the binding of CO with hemoglobin (Hb) in blood to form carboxyhemoglobin (COHb). In addition to cigarettes, another pollutant that might affect the COHb levels in the blood is the smoke produced from grilled food. AIM: Thus, this research was done to identify the difference in COHb levels in blood between grilled and non-grilled food vendors. METHODS: A comparative analysis study with a cross-sectional design was done between October and November 2020 at Jalan Dr. Mansyur, Medan. The sample for the measurement of COHb levels of each subject was taken from blood plasma. COHb levels were measured with Human COHb Elisa Kit, Size 96 Wells, Brands Bioassay TL at the integrated research laboratory of Universitas Sumatera Utara. Data analysis was done using SPSS version 24.0. Normality test of COHb levels in blood between grilled and non-grilled food vendors was done using Shapiro–Wilk test, where p > 0.05 indicated a normal distribution of data. RESULTS: A total of 50 subjects (25 from grilled food vendors and 25 from non-grilled food vendors) met the research criteria. Thirty-two subjects (64%) aged 20–30 years, where 19 of them were grilled food vendors (59.4%) and 13 (40.6%) were non-grilled food vendors. COHb levels were 500.22 ng/ml with minimum and maximum levels of 106.21 ng/ml and 1204.14 ng/ml observed, respectively. The median of COHb levels in grilled food vendors (352.81 ng/ml) was found to be lower than that in non-grilled (513.58 ng/ml). Comparative analysis results showed p = 0.204 (p > 0.05). CONCLUSION: There was no significant differences in COHb levels in blood between grilled and non-grilled food vendors in Medan.