This study is entitled ‘Evaluation of the Effectiveness and Validity of the Preparatory Year Programme at preparing Students for Studying in Taibah University’. Within the Taibah University, students are distributed to the various specializations at the university according to their results at the end of this preparatory year. It is a relatively new programme that has not been subjected to sufficient evaluation. The study explored the strengths and weaknesses of the programme with a focus on identifying ways to contribute to its improvement and development. The study used a mixed approach where the use of multiple linear regression was used to examine the ability of the admission criteria to predict the academic performance of programme students through examining the results of 3878 students. The results show that stronger acceptance criteria were provided by the achievement test followed by a student’s high-school mark and finally a capability test. To evaluate the effectiveness of the programme elements and the achievement of its objectives from the perspective of students and trainers, data was collected through 1972 student questionnaires, 98 trainer questionnaires and eight semi-structured interviews with students and four with trainers. Studying the effectiveness of the programme from the viewpoint of faculty members was done using 167 questionnaires and five semi-structured interviews. The results show the weaknesses of the university environment and the failure of the programme to meet its goals from the students’ and trainers’ viewpoints. The evaluation by faculty members of the effectiveness of the programme showed a positive view of the programme and expressed the view that students who have completed the programme have better skills and more knowledge than those who have not. The study recommended to allocate the largest proportion of a weighted percentage for acceptance to achievement test-results, followed by high school, and finally aptitude test-results. Furthermore, the study found that the teaching and assessment methods need to be reviewed, and the content and goals of the preparatory year programme would benefit from being re-aligned.