Introduction. Preterm birth is a relevant obstetric complication due to its high frequency and impact on neonatal health. Objectives. To analyze the association between urinary tract infection and threat of preterm birth in pregnant women. Methods. Observational, analytical, cross-sectional study conducted in Lima (2022–2024). A total of 179 pregnant women aged 18 to 45 years were analyzed. Threat of preterm birth and urinary tract infection were clinically classified. Poisson regression with robust variance was used to estimate adjusted prevalence ratios, with 95% confidence intervals and a significance level of p<0.05. Results. Threat of preterm birth occurred in 38.3% of participants, and urinary tract infection in 51.1%. No significant association was found between urinary tract infection and threat of preterm birth (adjusted prevalence ratio=1.09; 95% confidence interval: 0.77 ...