OBJECTIVE Noise, a common physical hazard in many workplaces, may affect different aspects of human cognitive function. In this study, the effect of exposure to noise on some aspects of cognitive function was assessed in industrial workers. METHODS This was a cross-sectional study on 84 individuals exposed to noise level higher than 85 dBA in a metal industry (noise group), comparing a group of workers from the same industry (n = 80) with exposure to noise level lower than 80 dBA (control group). The individuals in the noise group were classified as well according to noise intensity into: high exposure (90 dBA and higher) and low exposure (between 85 and 90 dBA). Selective attention score, divided attention score, selective response time, divided response time, and memory scale were measured before and after work shift. Data were analyzed by SPSS (Ver. 16) using Kolmogorov-Smirnov test, paired t test, Student's t test and Mann-Whitney U test were used to compare mean difference of the variables between two groups. p < 0.05 was considered as significant. RESULTS All measured cognitive functions were significantly changed after work shift in the noise group and the difference was statistically significant between noise and control group. Exposure to higher noise intensity caused more change in cognitive function. CONCLUSIONS Exposure to noise higher than 85 dBA affects some aspects of cognitive function (reaction time, attention and memory).