Against a background of differences in prevalence of chronic home oxygen therapy (CHO) and other pneumological tools (nasal continuous positive airway pressure, aerosol therapy, monitoring, assisted ventilation) found in studies of the various regions of Catalonia (Spain), we carried out a descriptive study to determine how these tools were being used in the northern Barcelona and coastal plain health region (population 657,376). Three hundred sixty-six (49.8%) patients used CHO, 39 (5.3%) used aerosol therapy, 52 (7.1%) used nasal continuous positive airway pressure, 3 (0.4%) were monitored at home and 1 (0.1%) was mechanically ventilated at home. Two hundred seventy-three patients about whom we had insufficient data did not keep their appointments with the doctor. Use of CHO was considered appropriate in 302 (82.5%) of the 366 patients reviewed; 6.5% of these were active smokers as indicated by measurement of CO in expired air. The number of patients resistant to treatment (273) is very high in the northern Barcelona and coastal plain region and should be followed up more carefully. Our finding allow us to estimate that CHO is appropriately prescribed in the northern Barcelona and coastal area for 87.5 patients per 100,000 inhabitants, a prevalence that is higher than that observed for other health regions in Catalonia.