Young drivers, having just passed a driving licence test and having been provided with the knowledge and skills necessary to participate in road traffic, cause the greatest numbers of road accidents. To investigate the reasons for such a situation, practical driving test results obtained by applicants for the B category driving licence were analysed. Within the analysis, the course of the practical tests under analysis was examined to identify the test task types with the highest numbers of successes and those most frequently causing the test to be failed. The task types that most often resulted in a failure in the driving test included left turn at an intersection, driving through a traffic circle, and, in general, disobeying the instructions given by road signs and failure to give way to other traffic participants according to the right-of-way rules. As many as 11 % of the examinees twice failed to perform satisfactorily the left-turn manoeuvre at an intersection. On the average, each of the examinees incorrectly carried out 7 tasks during the test drive and 21 % of the examinees committed disqualifying faults when performing only the first five test tasks. The diagnosis prepared has revealed severe deficiencies in the preparation of the examinees for safe participation in road traffic. Not only the test tasks have been identified where the highest numbers of faults were committed by the examinees but also the links between the tasks and the reasons for road accidents caused by young drivers have been shown.