This study aimed to develop a criterion – referenced test in Recipes letters Unit in Islamic education subject to measure the academic achievement of the grade eleventh students in unit's objectives. Moreover, the study aimed to investigate the psychometric properties of the test. The development of the test went through several stages: the test content was specified and was analyzed into behavioral measurable objectives, the items were written according to the method described by Popham for constructing criterion - referenced tests, Then judged for descriptive validity. The test was administered to a sample of 308 male and female students in Wilayat salalah in Dhofar Region. The psychometric properties of the test have also been investigated, the Descriptive Validity was Verified by content experts. Also, the reliability test were determined by Livingstone coefficient with different Lengths of tests and cut-off scores by gender. The results showed that the criterion - referenced test in Recipes letters Unit had both good validity and reliability.