Objective: Evaluate if pelvic inflammatory disease is a risk factor for the development of ectopic pregnancy. Method: This was an analytic retrospective case-control study in pregnant patients between 18-35 years, with and without medical history of ectopic pregnancy registered in the medical records of the Regional Hospital of Trujillo in the period from 2010 to 2015. A total of 34 cases and 68 controls were included. The data was analyzed in a tetrachoric chart determining the frequency of exposure between cases and controls, the presence of association between Xi square test with 95% confidence and strength of association by Odds Ratio. Results: It was evidenced that 23.5 % of the patients diagnosed with ectopic pregnancy had a medical history of pelvic inflammatory disease (PID), while 5.9 % of the patients without a diagnosis of ectopic pregnancy had a medical history of PID. Xi sig...