Purpose: Potential incompatibility (PI) between drugs infused together is frequent but under-recognized in intensive care units (ICU). This paper describes the frequency of the inappropriate coadministration of infused medications via the Y-site and identifies the most frequent and relevant drug incompatibilities in a single-center, cross-sectional observational study. Methods: This research was a retrospective cross-sectional study of 100 patients conducted between July and December 2019 in an ICU. The medical records of 100 patients in the ICU were collected, and their compatibility was assessed based on published compatibility data. Results: PI was detected in approximately 48.5% of patients (1.5 incompatibility/patient ratio). Most incompatibilities detected were classified as follows: the untested (84.4%), variable (9.7%), incompatibility (3.9%), or no data (1.9%). Acetylcysteine was the most frequent drug implied in PI. A difference was observed between the lengths of ICU and PI incidences (P=0.01). In the correlation between PI and APACHE II (Acute Physiology and Chronic Health Evaluation II), there was a weak correlation between APACHE II and PI (r=0.283, P＜0.05). Conclusion: PI is common in an ICU, with a higher prevalence of non-tested incompatibilities. The number of drugs and prescription of acetylcysteine, pantoprazole, meropenem piperacillin/tazobactam, or phytonadione are the risk factors for PI.