Objective To investigate the epidemic characteristics and spatial distribution patterns of varicella in Gulou District of Nanjing from 2013 to 2024, and to provide a scientific basis for optimizing prevention and control strategies and healthcare resource allocation. Methods The data of reported varicella cases in Gulou District of Nanjing were collected. Joinpoint 5.3.0 software was employed to analyze the trend in reported incidence rate of varicella, and ArcGIS 10.2 software was used to perform global spatial autocorrelation analysis and to identify hotspot areas. Results A total of 7 649 varicella cases were reported during the study period, with an average annual reported incidence rate of 55.99/100 000. The varicella outbreak generally showed an upward trend (AAPC=36.68%, 95%CI: 27.19%-60.93%). Case distribution exhibited seasonality, with a bimodal pattern: the primary peak occurred from October to January of the following year, and a secondary peak was observed in June. The male-to-female ratio was 1.20∶1. Crowds classified as students, kindergarten children and scattered children were more likely to suffer from varicella. The median age of patients from 2013 to 2020 [8(5, 13) years] was significantly lower than that from 2021 to 2024 [15(10, 22) years] (Z=-28.241, P<0.001). Global spatial autocorrelation analysis revealed significant spatial autocorrelation from 2016 to 2020 (P<0.05), indicating positive spatial correlation. Local spatial autocorrelation analysis identified a total of 17 “high-high” clustering areas, primarily concentrated in streets with high population density of the main urban area, which was consistent with the high-incidence regions identified by descriptive analysis. Conclusion The reported incidence rate of varicella in Gulou District of Nanjing from 2013 to 2024 shows an overall upward trend and a significant spatial clustering. These clustering areas are predominantly located in the central urban areas characterized by high population density and high transmission risk. The high-risk age for varicella is shifting older. It is recommended to strengthen varicella surveillance during peak periods and in key areas, and to continuously implement varicella vaccination targeting high-risk populations.