BACKGROUND Ectopic pregnancy (EP) is the most frequent cause of maternal death in the first trimester of pregnancy. The objective was to establish the clinical features and risk factors associated with EP. METHODS Observational, retrospective, transversal and analytic case-control study. Two groups were included: the cases group (28 patients) and the control group (56 postpartum patients). Univariate and bivariate descriptive statistical analysis were carried out using the Pearson chi-square test, p < 0.05, with odds ratios (OR) and 95% confidence intervals (95% CI). RESULTS Statistically significant values (OR) were: smoking: 18.33, history of EP: 11.96, IUD use: 11.9, abdominal surgery: 5.87, being multigravid: 3.80, and having two or more sexual partners: 2. The most common clinical symptom was pelvic pain with 57.1% (16), right ruptured EP 53.6%, tubal pregnancy 82.1% (23), unruptured EP 60.7% (17), hemoperitoneum 60.7% (17). Gestational age for EP was of 4-8 weeks (75%) and surgical treatment 96.4%. CONCLUSIONS The frequency of EP found in our population was 1 in every 122 live births. Risk factors associated with ectopic pregnancy with statistically higher values were: smoking, being multigravid, having a clinical record of EP, IUD use before conception, abdominal surgery. The more frequent clinical characteristics were pelvic pain, right EP, tubal pregnancy, EP with no ruptures, hemoperitoneum < 750 ml, a gestational age between four and eight weeks.