Objective: To evaluate the usefulness of the Protein/Creatinine index (CPI) in a random urine sample, comparing it with 24-hour urine proteinuria, in patients with suspected pre-eclampsia. Methods: Cross-sectional study of a diagnostic test, random, comparative, observational, non-experimental, carried out between September 2018 - September 2019, at the Obstetrics and Gynecology Division of the Maracaibo University Hospital, Dr. Armando Castillo Plaza Maternity. 30 patients were selected. To determine the validity of the Protein/Creatinine index, the following were calculated: Sensitivity,Specificity, Positive Predictive Value, Negative Predictive Value, positive and the Receiver Operating Characteristic curve. The correlation between Protein/Creatinine index and 24-hour proteinuria was assessed using a two-way correlation plot and Spearman’s correlation coefficient. Results: The sensitivity of the Protein/Creatinine index was 90% and the specificity of 80%, with a Positive Predictive Value 90, and a Predictive Value negative 80, Positive Likelihood Ratio: 4,58, Negative Likelihood Ratio: 0.12. The Receiver Operating Characteristic curve indicated an area under the curve of 0.848, which means that there is an 84% probability that the Protein/Creatinine index was positive in proteinuria, with a cut-off point of 0.3. Conclusions: The Protein/Creatinine index is a reliable diagnostic tool that can easily be interpreted by trained health personnel, comparable to 24-hour proteinuria, with advantages such as saving time and easy interpretation. Keywords: Preeclampsia, Urine sample, Proteinuria, Creatinine.