AIM: The aim of the present study was to evaluate the anthropometric parameters and the body composition through bioelectrical impedance analysis on paediatric subjects with dental agenesis. MATERIALS AND METHODS: The study was conducted on 144 subjects (58.3% females and 41.7% males), aged 7-14 years (average age 10.22±2.53 years). Each patient underwent a dental check-up at the Paediatric Dentistry Unit, University of Rome Tor Vergata (Italy) and a nutritional evaluation, aimed at analysing the anthropometric characteristics and evaluating the indices of body composition through bioelectrical impedance analysis (BIA) at the Human Nutrition Unit, University of Rome Tor Vergata. The sample was divided into three groups: a group with single agenesis (Group 1), a group with multiple agenesis (Group 2) and a control group (Group A). Using the predictive equations, the following values were evaluated: resistance (R), reactance (Xc), phase angle (PHA), body cell mass index (BCMI), body cell mass (BCM), total body water (TBW), intracellular water (ICW), extracellular water (ECW), fat mass (FM), fat free mass (FFM). STATISTICS: The Excel environment and the SAS System, version 9.3, were used for statistical analysis, providing a descriptive and parametric analysis of the sample. The values of the anthropometric parameters were expressed as mean ± standard deviation. For the statistical analysis of anthropometric parameters and body composition, analysis of variance (1-way ANOVA) was used, which allowed us to find differences and the Student's t-test to compare Groups 1, 2, and A. RESULTS: There is a significant difference in the resistance R value between the case group with single agenesis (Group 1) and the control group (Group A) (R, 710.28±72.46 vs 667.4±104.16, p=0.028), and the phase angle PHA between the case group with multiple agenesis (Group 2) and the control group (Group A) (PHA, 5.18±0.48 vs 5.85±1.05, p=0.028). The BCM% value shows a significant difference between both Group 1 and Group A (BCM%, 50.53 ± 3.29 vs 52.68 ± 4.74, p=0.016) and between Group 2 and Group A (BCM%, 49.25± 2.86 vs 52.68 ± 4.74, p=0.035). The TBW, ICW, ECW, FM, FFM values showed no significant differences between the various groups analysed. CONCLUSION: Body composition in subjects with dental agenesis presents a higher R, a consequently lower PHA and a lower BCM% compared to the control group. For the first time, the results highlighted the possible relationship between dental agenesis and body composition, measured through BIA.