Introduction: In popular opinion, costs are equated with expenses, in other words, by costs we mean amounts that have to be spent on something. So, we often talk about health costs, when in fact we mean health expenditure, that is, all monetary expenses incurred in the framework of the health system. Methodology: This is a descriptive cross-sectional study with an analytical aim on the cost and the clinical and epidemiological aspects of diseases with weekly notification in children aged 0 - 5 years at the Chrina Medical Center, at the General Referral Hospital of Kamalondo and at the Katuba General Referral Hospital on 203 children aged 0 - 5 years during the first quarter of 2019. Results: The average cost of treating malaria at Chrina Medical Center is $60.2, it is $69 at Kamalondo General Referral Hospital and $77.6 at Katuba General Referral Hospital. Compared to clinical signs, all patients (100.0%) presented with Fever, 75.0% presented with Rash and only 50.0% presented with physical asthenia. Out of 203 cases identified malaria (88 cases), typhoid fever (78 cases), acute respiratory infections (33 cases) as well as measles (4 cases). Conclusion: Prevention is the best way to fight most of the communicable diseases which cause enormous damage both individually and collectively. There is an urgent need for health education to inform and educate the population on individual and collective hygienical measures as well as the risks related to the immediate environment, in particular, the lack of access to drinking water, sanitation, decent housing and a healthy living environment is among the factors behind the poor health of children under five in developing countries.