Clinical pharmacology is an integral part of oncology, especially in the modern era of precision medicine.The innovations introduced in drug development (conditional accelerated tumor-agnostic approvals through adaptive trials) and clinical practice (liquid biopsy, tumor molecular board) underline the pressing need for clinical pharmacologists, who play a catalyst and translational role in a synchronized multidisciplinary team. This review describes the latest advancements and challenges in actually implementing the precision medicine approach in oncology: pharmacovigilance, drug interactions, pharmacogenetics and therapeutic drug monitoring are often overlooked valuable tools for the understanding, detection, assessment, and prevention of adverse drug reactions, thus supporting safe prescribing in oncology.