We developed a computer program for the optimization and management of data collection in order to compute the change of forced expiratory volume in the first second (delta FEV1), provocative doses and to plot the dose-response curve for bronchial challenge test. Doses of methacholine are entered via the keyboard and forced vital capacity (FVC) with the highest FEV1 value obtained in each step is selected. When the imposed threshold of response has been reached, doses of administered methacholine and corresponding spirometric parameters are displayed and printed. Dose-response relationships are analysed: the increase of delta FEV1 for each unit of metacholine is computed in the interval between the two doses where delta FEV1 reached one of the imposed values (i.e. 15% or 20% or 30%). Finally spirometric values, dose-response curve and provocative doses are shown in a print-out. Computer values of provocative doses are higher than those obtained manually. This difference may be ascribed to the incorrect manual linear extrapolation. In conclusion the computer program is able to reduce consistently the time spent to analyze data from bronchial challenge test and allows a more precise determination of provocative doses by avoiding also inter-intra individual errors.