Background: Interleukin (IL)-1β stimulates the proliferation and differentiation of osteoclast precursors into mature osteoclasts. IL-1B polymorphisms may influence the gene and protein expression of IL-1β. The present study aimed to investigate the association of IL-1B variants (rs2853550, rs1143643, rs3136558, rs1143630, rs1143627, rs16944 and rs1143623) and their interaction with osteoporosis risk among the northwestern Chinese Han population. Methods: AN Agena MassARRAY system (Agena, San Diego, CA, USA) was employed for genotyping in 594 osteoporosis patients and 599 healthy controls. The possible association between IL-1B polymorphisms and risks of osteoporosis development was identified with odds ratios (OR) and 95% confidence intervals (CI) using logistic regression models. Haplotype analysis and multifactor dimension reduction analysis were used to explore the potential association between combined single nucleotide polymorphisms (SNPs) and osteoporosis risk. Results: The AA genotype of rs2853550 was a protective factor for osteoporosis occurrence (OR = 0.11, p = 0.038), whereas rs16944 (OR = 1.19, p = 0.037) and rs1143623 (OR = 1.21, p = 0.025) conferred an increased risk of osteoporosis. Moreover, rs1143627, rs16944 and rs1143623 were associated with an elevated susceptibility to osteoporosis, especially in females and individuals aged > 60 years or with a body mass index > 24 kg/m 2. Haplotype G rs1143630 A rs1143627 G rs16944 was a risk factor of osteoporosis occurrence (OR = 1.20, p = 0.032). The best model of SNP-SNP analysis was a four-locus combination of rs1143643, rs3136558, rs1143630 and rs1143623 (testing accuracy = 0.5623). Conclusions: IL-1B polymorphisms and haplotype G rs1143630 A rs1143627 G rs16944 might contribute to susceptibility to osteoporosis. The SNP-SNP interaction of polymorphisms in IL-1B revealed the accumulated effect on osteoporosis risk.