This book offers a comprehensive exploration of Fenbendazole, a widely used anthelmintic drug initially developed for veterinary medicine. It covers the pharmacology, clinical applications in animals and emerging interest in human medicine, including potential anticancer effects. The book also addresses important issues like safety and toxicity, drug resistance, and environmental impacts. Practical topics such as formulations, administration methods, and legal regulations are discussed in detail. Case studies and clinical experiences provide real-world insights, while the appendices offer valuable dosage guidelines, pharmacokinetic data, and further resources. Finally, the book highlights future research directions, emphasizing the need for innovation, sustainable use, and rigorous scientific study to maximize Fenbendazole's benefits across species.