Otosclerosis is a disease of abnormal bone remodeling in the human otic capsule that can lead to progressive hearing loss. Little of the underlying disease etiology has been elucidated thus far, although several studies have suggested that COL1A1 may play a role based on its importance in bone metabolism and other diseases like osteoporosis and osteogenesis imperfecta. Genetic association studies between COL1A1 and otosclerosis, however, have been contradictory. To resolve this issue, we studied a large Belgian-Dutch and a Swiss population for a genetic association between COL1A1 and otosclerosis and additionally performed a meta-analysis to investigate the overall genetic effect of COL1A1 on all otosclerosis populations studied to date. We found a significant association both in the Belgian-Dutch population and in the meta-analysis. In aggregate, our analysis supports evidence for an association between COL1A1 and otosclerosis although effect sizes of the variants reported in the initial studies are likely to be an overestimate of true effect sizes. © 2012 Wiley Periodicals, Inc.