Background: Syphilis has reemerged as a significant public health issue in Chile. This study analyzes trends and the sociodemographic distribution of cases reported 2018-2022, including co-infections and behavioral factors. Aim: To characterize the epidemiological trends of syphilis in Chile between 2018 and 2022 and describe associated demographic and clinical factors. Methods: Descriptive, cross-sectional study with an ecological component, based on the EPIVIGILA national registry (2018-2022). Sociodemographic, clinical, and behavioral variables were analyzed;" rates per 100,000 inhabitants-year were estimated using projections from the National Institute of Statistics (INE). The associations were evaluated with chi 2 (p < 0.05). Results: There were 38,467 reported cases of syphilis, predominantly in its early stages (51.6%) and in men (65%). Coinfection with other STIs was 25.8%. Only 6.3% reported consistent condom use. 19.5% of cases involved foreigners. Regional disparities in incidence rates were observed. Conclusion: Syphilis continues to rise in Chile, especially among young men and the migrant population, with significant regional disparities. The findings support the need for targeted strategies that include sociodemographic and behavioral factors."