Previous studies on the associations of the NFKB1 -94 insertion/deletion polymorphism with cancer risk have produced conflicting results. The purpose of this meta-analysis is to define the effect of the NFKB1 -94 insertion/deletion polymorphism on cancer risk. A search of the literature by PubMed was performed to identify studies based on the predetermined inclusion criteria. Twenty-three studies consisting of 6,494 cases and 9,884 controls were identified and analyzed. Overall, significant association was observed between the polymorphism and cancer risk under all genetic models. Subgroup analysis according to ethnicity and cancer type also detected significant association. The NFKB1 -94 insertion/deletion polymorphism was associated with cancer risk in Asian population (dominant model: OR=1.52, 95 % CI=1.17-1.98; recessive model: OR=1.50, 95 % CI=1.26-1.79; II vs. DD: OR=1.90, 95 % CI=1.37-2.65; ID vs. DD: OR=1.32, 95 % CI=1.05-1.66; I vs. D: OR=1.37, 95 % CI=1.17-1.60), but not in Caucasian population. In addition, significant associations in OC, HCC, and OSCC were observed, but significant associations were not found in BC and LC. The current meta-analysis suggested that NFKB1 -94 insertion/deletion polymorphism may influence cancer risk in Asian population.