Abstract Background and Aims Nephrogenic diabetes insipidus (NDI) is a rare inherited disorder, and there is a paucity of studies assessing long-term clinical outcomes in affected individuals. This study aims to evaluate the long-term clinical outcomes, encompassing growth and kidney function, in pediatric patients with NDI. Method This multicenter retrospective study included forty-nine children diagnosed with NDI. The medical records of these patients were retrospectively reviewed, and a linear mixed model was employed to analyze variations in growth and kidney function with increasing age. Results Mutations in the AVPR2 and AQP2 genes were identified in 40 (81.6%) and 4 (8.2%) patients, retrospectively, while pathogenic variants were either not found or not tested in 5 (10.2%) patients. The median ages at diagnosis and the last follow-up were 0.41 (interquartile ranges (IQR) 0.12−0.64) years and 9.97 (IQR 2.42−18.66) years, respectively. Thiazide treatment was administered to all patients, with 43 (87.8%) and 14 (28.6%) patients also receiving amiloride and indomethacin, respectively, in conjunction with thiazide. Our analysis using linear mixed models revealed significant changes in growth including height, weight, and body mass index (BMI) with increasing age. The estimated marginal means (EMM) for height Z score decreased from −0.114 (95% confidence interval (CI) −0.507 to 0.279) at diagnosis to −1.464 (95% CI −1.880 to −1.048) at 2 years of age, subsequently increasing to −0.706 (95% CI −1.186 to −0.225) at 14 years of age (P < 0.001). The height Z score at 19 year of age is −0.899 (95% CI −1.434 to −0.365), significantly lower than those at diagnosis (P = 0.038). The EMM for weight Z score increased from −1.580 (95% CI −2.009 to −1.149) at one year of age to 0.760 (95% CI 0.170 to 1.350) at 19 years of age, exhibiting a steady increase (P < 0.001). The EMM for BMI Z score demonstrated a consistent increase after age of 2 years (P < 0.001), which were −0.326 (95% CI −0.835 to 0.182) at 2 years of age and 1.210 (95% CI 0.602 to 1.817) at 19 years of age. The proportion of obesity increased from 3.2% at 3 years of age to 33.3% at 19 years of age. The EMM for estimated glomerular filtration rate (eGFR) consistently increased from 82.8 (95% CI 75.2 to 90.3) mL/min/m2 to 100.8 (95% CI 88.9 to 112.7) mL/min/m2. Although eGFR less than 60 mL/min/m2 is not present, the eGFR less than 90 mL/min/m2 is 47.5% at last follow up. Conclusion At the end of growth, the height Z score is low, and the proportion of obesity is high. To improve the growth pattern, clinicians need to monitor nutritional status and establish nutritional support during follow-up in patients with NDI. Since mild decreased kidney function developed in half, patients with NDI need long-term follow-up evaluation for kidney function.