Research plays an important role in the development of countries, which positively impacts all sectors, especially health and education. In Saudi Arabia, there are insufficient studies that evaluate knowledge, attitude, and barriers (KAB) towards research among Physical Therapy (PT) undergraduate students. Therefore, this cross-sectional study evaluated the attitude, knowledge and barriers towards research among PT students in five Saudi universities as well as the effects of the socio-demographic characteristics on the above three variables. An online questionnaire for measuring KAB towards research was circulated to PT students in five Saudi universities. Descriptive statistics, independent sample t-test and one-way analysis of variance were used for analysis. The outcomes revealed a positive attitude towards research, but the students lacked research knowledge, and majority of responses to barriers were related to lack of research applications in personal life and professional job. It was found that females have higher knowledge than males (P = 0.021), whereas School of education and household monthly income showed no significant effect on AKB towards research. This study concludes that PT students in Saudi Arabia have moderate positive attitude, lower knowledge, and high barriers towards research.