Primary spontaneous pneumothorax is a common abnormality for which there is a variety of treatments. This study presents the results of a year's evaluation of a clinical pathway (CP). A series of 34 patients treated during 1 year before CP development was analyzed to identify the weak points. To address these weak points, the CP includes associated protocols. In the CP, 31 patients were evaluated during 1 year; the results were compared with those of the pre-CP series. The mean length of stay of the pre-CP patients and the CP patients was 7.3 days and 5.0 days, respectively. The number of radiographs fell from 4.3 to 3.2. The rate of complications and readmissions is similar in both groups. The mean cost per process dropped from 1863 [UNKNOWN] to 1168 [UNKNOWN]. The CP for pneumothorax successfully manages to reduce both the variability in care patterns and hospital costs, justifying the work involved in its development and implementation.