Historically, psychologists have considered obsessive-compulsive disorder (OCD) a challenging disorder to treat, with significant numbers of patients failing to benefit from treatment. The heterogeneity of the population and the complexity of the disorder have been contributing factors. However, cognitive-behavioral treatments are showing great promise, particularly when delivered with pharmacotherapy and tailored to the unique characteristics of each OCD subtype. The chapters in this volume, written by prominent specialists, provide practical, step-by-step descriptions of psychological approaches to treating OCD. After explicating the general, underlying features of the disorder, the contributors to this volume describe evidence-based behavioral and cognitive approaches, such as exposure and ritual prevention and cognitive restructuring. Subsequent chapters discuss how to apply these strategies with particular presentations of OCD, including fears of contamination; doubting and checking; incompleteness concerns; religious, sexual, and aggressive obsessions; and compulsive hoarding. Practitioners experienced in treating this disorder will appreciate the discussion of more advanced issues, including dealing with treatment resistance and comorbidity and treating OCD in special populations. All readers will find in this book a practical and insightful guide for helping individuals with this troubling disorder.