Recent studies have shown that fluticasone propionate (FP) was more effective than beclomethasone dipropionate (BDP) inhalation even at a dose reduced by twofold or more in the treatment of bronchial asthma. Here, we further compared the effectiveness of FP and BDP, including rates of drug compliance. Forty-two symptomatic patients were treated by BDP (1000 +/- 345; mean +/- SD; microgram/day) for 8 weeks, followed by FP at one-half the respective dose, and peak expiratory flow and forced expiratory volume in 1 second were investigated. In addition, the patients were asked about drug compliance and factors related to compliance (expressed using a visual analogue scale). Significant increases of peak expiratory flow (from 316 +/- 96 L/minute to 345 +/- 86 L/minute) and forced expiratory volume in 1 second (from 1.7 +/- 0.5 L to 1.9 +/- 0.4 L) were found. Furthermore, significantly higher scores were obtained for compliance and various factors related to compliance. These data indicate that FP is more effective than a twofold higher dosage of BDP and that better compliance with the use of FP, probably because of improved various factors associated with FP compliance, contributes to FP efficacy.