Aim: To investigate the relationship between aluminum and spontaneous pneumothorax (SP) development. Materials and methods: A patient group and a control group were formed with 100 individuals in each. The serum aluminum levels of the groups were determined and statistically compared. Results: The mean serum aluminum levels were 5.6 ± 2.4 μg/L (1.6-11.9) and 23.2 ± 15.4 μg/L (2-81) in the control and SP groups, respectively (P < 0.001). The specificity and sensitivity of the measurement of aluminum level were 74.4% and 86.4% in the SP group. The risk of SP development was found to be 18 times higher in individuals with high serum levels of aluminum compared to that in individuals with low serum levels of aluminum. Conclusion: A high level of aluminum is a risk factor for the development of SP. © TÜBİTAK.