Shortages of available drugs suitable for pediatric patients (infants, children, and adolescents) play a central role in the increased demand for compounded medicines. A doctor tends to give the similar prescription for the patients with the same clinical condition. This will form a pattern in prescribing. This research aims to find the pattern of compounded medicines prescribing (in the form of association rules) done by the doctors and stored in forms of data mining using Algorithm FP Growth Analysis. The result of this pattern can be used as the proposal to determine the supplies of brand-name medicine in the hospital pharmacy.