Diarrheal disease remains a significant cause of child mortality, particularly in regions with limited access to healthcare and sanitation. Inappropriate practices, including unjustified medication prescriptions, pose challenges in the management of acute diarrhea (AD), especially in low- and middle-income countries. This study analyzed antibiotic prescription patterns and assessed compliance with Integrated Management of Childhood Illness (IMCI) guidelines in children under 5 with AD in the Ministry of Public Health (MOPH) Ambulatory Care Centers of Quito city, Ecuador. A cross-sectional design was used, collecting electronic health records (EHR) of patients diagnosed with AD from 21 health facilities in District 17D03. A probabilistic and stratified sampling approach was applied. Patient characteristics, prescriber characteristics, treatments, and compliance of IMCI guideline recommendations were evaluated. A stepwise logistic regression analysis examined the association between antibiotic prescription and patient and physician characteristics. A total of 359 children under 5 years of age were included, with 58.77% being girls. 85.24% of the cases of AD were attributed to gastroenteritis and colitis of infectious and unspecified origin. Amebiasis and other protozoal intestinal diseases accounted for 13.37% and 1.11% of the cases, respectively. The completion rates of recording various IMCI parameters varied; parameters such as duration of diarrhea, presence of blood in stool, and evidence of sunken eyes had high completion rates (100%, 100%, and 87.47%, respectively), while parameters like state of consciousness, presence of thirst, and type of diarrhea had low completion rates (0.28%, 0.28%, and 0.84%, respectively). None of the cases had all parameters fully recorded. Antimicrobials were prescribed in 38.72% of the cases. Children aged 3 to 5 years had higher odds of receiving antimicrobial prescription for AD (aOR: 4.42, 95% CI 2.13-9.18, P < .0001) compared to those under 1 year, after adjusting for the number of loose stools per day, gender, and age of the health professional. Variations in IMCI guideline compliance were observed, with no cases fully adhering to the guidelines. Antimicrobial prescription rates were notably high, especially among older children. Further research and specialized interventions are necessary to gain comprehensive insight into the factors underlying non-compliance with the IMCI guidelines.