The stability of theophylline (T) and propranolol hydrochloride (P) in extemporaneously compounded oral suspensions (25 mg/mL or 50 mg/mL for T and 2 mg/mL or 5 mg/mL for P) were studied. Suspension with P and T were prepared with bulk substance or tablets using three different suspending vehicles: Ora-Sweet (M1), modified Ora-Sweet (M2) and simple syrup with glycerol and sorbitol (M3). Each suspension was stored for 35 days in a dark place at 25 degrees C and 4 degrees C. The results demonstrated that the prepared suspensions with P either from tablets or from a substance were stable in all three studied vehicles (more than 95% of initial concentration remaining). However, it is recommended that storage at 4 degrees C of suspensions prepared with M2 should be avoided because of crystallization of the buffer substances. Extemporaneous suspensions with T in an appropriate pediatric concentrations of the drug were not obtained because the problem of fast crystallization of T was not eliminated.