The role of glutathione S-transferase Mu 1 (GSTM1) in the biomonitoring of polycyclic aromatic hydrocarbons (PAHs) is not clear. Our purpose has been to evaluate the influence of GSTM1 genotypes on 1-hydroxypyrene (1-OHP), deoxyribonucleic acid (DNA) adducts, and micronucleus frequency in both occupational and non-occupational populations of null and active GSTM1 carriers. We conducted a meta-analysis on 25 articles that met our strict inclusion criteria (11 studies on 1-OHP, 9 on DNA adducts, and 5 on the micronucleus frequency). In the case of occupationally exposed workers, micronucleus frequency was only significantly higher in the null GSTM1 carriers than in the active GSTM1 carriers. In the non-occupationally exposed general population, 1-OHP and micronucleus frequency were significantly higher in the null GSTM1 carriers. The results of Egger’s test and funnel plot analysis indicated no significant publication bias. In conclusion, GSTM1 genotypes may affect the urinary 1-OHP in the non-occupationally exposed general population, and micronucleus frequency in both occupational workers and non-occupational population. Int J Occup Med Environ Health 2017;30(2):177–201