Objectives: Disagreement between health care providers on medication-related interventions can affect clinical outcomes. We aimed to study the outcomes and significance of clinical pharmacists’ interventions and evaluate the levels of agreement between different clinical pharmacists on the impact of pharmaceutical interventions. Methodology: A retrospective study was conducted at a tertiary care hospital in Oman. The study included all documented interventions by clinical pharmacists for all categories of admitted patients that met the inclusion criteria. Results: The originator clinical pharmacists interjected to improve the efficacy of treatment in (58%, n=1740) of the interventions, followed by toxicity reduction (24%). The level of agreement in the clinical significance resulted in substantial Scotts’ kappa (k) between the originator and the first reviewer, the first and second reviewers, and the second reviewer and supervisor (86%; k=0.77; P.001), (77%; k=0.63; P.001), (84%; k=0.77; P.001), respectively. In terms of grading of clinical significance, the originator clinical pharmacists recorded moderate significance in 50% of the interventions, followed by major (30%), not applicable (8.4%), and minor (7.3%). The level of agreement in the clinical significance resulted in substantial Scotts’ k between the originator and the first reviewer, and between the second reviewer and supervisor (82%; k=0.72; P.001), (84%; k=0.77; P.001), respectively. The level of agreement between the first and second reviewer was fair (55%; k=0.28; p0.001). Conclusion: Clinical pharmacists’ interventions have a crucial impact on patient safety, improving efficacy and reducing toxicities.