The deposition of budesonide at fast (60 l min−1) and slow (30 l min−1) inspiratory flow rates from AirmaxTM, a new multi-dose dry powder inhaler, was compared with that from Turbuhaler® and a standard pressurized metered dose inhaler (pMDI). Twelve patients with mild to moderate asthma took part in a five-way randomized cross-over study, and inhaled a single nominal dose of 200 μ g budesonide, labelled with 99mTc, on each study day. Deposition was determined by gamma scintigraphy.At the fast flow rate, AirmaxTM and Turbuhaler® deposited 25·8±6·5% (mean±SD) and 29·8±6·9%, respectively, of the delivered dose in the whole lung (P=0·080). At the slow flow rate, AirmaxTM deposited 28·3±5·6%, Turbuhaler® 22·7±5·6% and pMDI 12·1±3·4%. Using data on emitted doses determined in vitro, it was estimated that AirmaxTM deposited 53·1±13·3 μ g and 43·6±8·6 μ g budesonide in the lungs at 60 l min−1 and 30 l min−1 respectively, whilst Turbuhaler® deposited 48·3±11·2 μ g at 60 l min−1 and 24·2±6·0 μ g at 30 l min−1.In conclusion, lung deposition of budesonide from AirmaxTM was comparable to that of Turbuhaler® at a high flow rate but was markedly superior to Turbuhaler® and pMDI at a lower flow rate. Unlike Turbuhaler®, AirmaxTM performs with relative flow–rate independence.