Work has been initiated in Pharmacology and Toxicology Department since the inception of the College of Pharmacy at Umm Al-Qura University as one of the five basic departments in the college. Since establishment of the department, all staff have been showing keen interest in development of courses in terms of modernization of teaching methods and facilities to be consistent with the requirements for graduation of a competent pharmacists from college of pharmacy in both programs according with the labor market needs.

The department is responsible for teaching many courses throughout the year including pharmacology, clinical pharmacology, and toxicology (basic and clinical). Pharmacology is the study of how chemical agents, both natural and synthetic (i.e., drugs) affect biological systems. This encompasses investigation of the chemical properties, physiological and behavioral effects, and mechanisms of action, biological transformations, and the therapeutic and non-therapeutic uses of drugs.

Clinical pharmacology is underpinned by the basic science of pharmacology, with added focus on the application of pharmacological principles and methods in the real world. Toxicology is the scientific study of adverse effects that occur in living organisms due to chemicals. It involves observing and reporting symptoms, mechanisms, detection and treatments of toxic substances, in particular relation to the poisoning of humans. Also, the department of pharmacology is keen to encourage research into the most relevant areas in pharmacology and toxicology.