Evaluation plays an enormous role in the teaching-learning process. It helps teachers and learners to improve teaching and learning. Evaluation is a continuous process and a periodic exercise. In learning, it contributes to formulation of objectives, designing of learning experiences and assessment of learners‟ performance. It is very useful to bring improvement in teaching and curriculum. It also provides accountability to the society, parents, and to the education system.A teacher-made test is one of the most valuable instruments in the hands of the teacher to achieve his purpose. It is designed to solve the problem or requirements of the class for which it is prepared and to measure the outcomes and content of local curriculum. It is very much flexible so that, it can be adopted to any procedure and material. It does not require any sophisticated technique for preparation. This study aims at: 1- identifying a set of criteria for efficient English teacher-made tests. 2- evaluating English teacher-made tests of the fifth preparatory class in the light of the criteria developed. The following procedures are followed in order to achieve these aims: 1.Designing a checklist which includes the most important criteria of efficient tests, namely: validity, reliability, practicality (scorability) and accuracy. 2-Selecting a sample of eighteen teacher-made tests for the fifth preparatory class.3-Evaluating the efficiency of the selected sample of teacher-made tests in terms of the identified criteria. 4-Interviewing a sample of EFL preparatory school teachers for revealing the reasons behind the errors that have been found in the evaluated test papers.The findings of the study identify a number of defects in teacher-made tests including, invalid questions, questions of low validity, affected reliability, affected scorability and inaccurate questions in punctuation and in grammar. Then the study ends up with some conclusions and recommendations for improving teacher-made tests.