Objective: In this study, we aimed to illustrate the physician’s practice of pharmacokinetics in the Kingdom of Saudi Arabia.Methods: This is a cross-sectional survey conducted to assess the practice of pharmacokinetics services by physicians in the Kingdom of Saudi Arabia. In this study, we used a self-reported electronic survey questionnaire and distributed to physicians from interns to consultants and specialists in Saudi Arabia. The survey collected demographic information of the responders. Application of pharmacokinetic practice in medical care, often at pre-dose or post-dose levels required in medical care medications requiring the pharmacokinetics services. We used 5-point Likert response scale system with close-ended questions to obtain responses. The data were collected through the Survey Monkey system and analyzed using the Statistical Package of Social Sciences (SPSS), Jeffery’s Amazing Statistics Program (JASP), and Microsoft Excel software version 16 were.Results: A total of 259 physicians responded to the survey, with the majority of them coming from the southern region (98 (39.36%)). among them, 107 (44.96%) were male and 131 (55.04%) were female responders, and there was no statistically significant difference between them (p=0.120). Most of the physicians were residents (74 (29.48%)), followed by specialists (69 (27.49%)) and interns (68 (27.09%)), with statistically significant differences between them (p=0.010). The average score for the practice items for pharmacokinetics services by physicians was 3.24, with high scores obtained for the elements the vision of pharmacokinetics services system (3.76), pharmacokinetics services and medications errors system (3.40), and pharmacokinetics services and quality management (3.34), with statistically significant between the responses (p=0.000). The most of medication that had been requested for blood levels asked or observed were gentamicin 133 (57.83%), amikacin 45 (44.12%), and vancomycin 39 (33.05%). The highest scores of pharmacokinetics services or therapeutic drug monitoring are the clinical pharmacist’s responsibility (4.37) and nurses (4.23). Test reliability analysis of McDonald’s ω (0.829), Cronbach’s (0.774), Gutmann’s λ2, (0.792), and Gutmann’s λ6 (0.880).Conclusion: The practice of pharmacokinetics services was found to be insufficient in the Kingdom of Saudi Arabia. Therefore, we recommend the implementation of pharmacokinetics services in medical care to prevent drug-related morbidity and mortality. Moreover, improving patient clinical outcomes in medical care in Saudi Arabia.