The present study aimed to determine the effects of a computerized dynamic reading assessment (CDRA) program on English reading comprehension of university students with a lower level of English proficiency. Fulcher's (2003) framework was adapted in program development divided into three phases: program development, program implementation, and program evaluation. An intact group of 30 Thai EFL undergraduate students with a lower level of English proficiency participated in this mixed-methods study which employed a test-train-test approach. Quantitative data collected from non-dynamic assessment (DA) pre- and post-tests as well as five DA tests were analyzed by means of inferential statistics, while qualitative data elicited from the questionnaire and interview protocol were analyzed using descriptive statistics and content analysis. The findings revealed that the CDRA program had a positive effect on the students' reading comprehension, as demonstrated by the post-test results and a large effect size. Qualitative analysis revealed that the students had a positive perspective on the advantages offered by the CDRA program, expressed a preference for the software, and offered opinions and suggestions for further improvement. The findings of this study yield implications and recommendations for EFL instructors of English reading courses regarding the design of the CDRA programs interface and its utilization.