Chronic nonsteroid-dependent childhood asthma was treated by adding beclomethasone dipropionate (BDP) or placebo (P) to the daily regimen of theophylline (T). Subjects (6-12 years) were selected based on daily control of asthma by T at necessary T levels in sera of 10-20 micrograms. Active BDP (200 micrograms b.i.d.) and P groups were randomly assigned. Each subject's baseline values were evaluated on a 4-week open phase followed by a 10-12 week double-blind phase. Daily diaries were kept for signs, symptoms, Wright peak flow recordings, and medication requirements. Visits were monitored for urine and serum cortisols, pulmonary function tests (PFT), objective changes, and medication compliance. Demographics between both groups were nonsignificant (NS). Baseline PFTs in P group were significantly better than the BDP group. Serum and urine cortisols and ACTH responses were NS (p less than 0.05). Drug efficacy for asthma characteristics was significantly improved in the BDP group (p less than 0.05) only. The BDP group maximized their response by 8 weeks, with improvement of their FEV1 and FEF25-75 PFT. Thus, b.i.d. BDP provided good asthma control and the twice-daily program should insure improved compliance.