Kidney stone is characterized by a high incidence and recurrence rate, and although previous studies have demonstrated that obesity increases the risk of nephrolithiasis, the causal relationship between kidney stone and internal adipose tissue remains unclear. This study used data from the National Health and Nutrition Examination Survey2011-2018 to explore the association between visceral adipose tissue (VAT) and kidney stones in a cross-sectional study. Various analysis methods were used, including multivariate logistic regression, limiting cubic spline analysis, and receiver operating characteristic. In addition, a 2-sample Mendelian randomization (MR) analysis was performed to evaluate the potential causal relationship between VAT and kidney stones. The combined design strengthens causal inference. The study looked at a sample of 9646 participants, comprising 4949 males and 4697 females. The results of the study suggest that higher VAT levels are associated with an increased risk of kidney stones (OR = 3.59, 95% CI = 2.671-4.825, P < .001). Restriction cubic spline analysis showed a nonlinear correlation between VAT and nephrolithiasis, with a turning point at 442.9 g of VAT. The receiver operating characteristic curve showed that VAT had a more accurate predictive effect on kidney stones. Finally, 2-sample MR analysis confirmed a positive causal relationship between VAT and the risk of kidney stones (OR = 1.16, 95% CI = 1.02-1.31, P = .016). This investigation revealed a statistically significant association between VAT deposition and kidney stone. Our results also suggest that the relationship between VAT and kidney stone is nonlinear. VAT reduction may represent a potential preventive approach, pending confirmation in longitudinal studies.