In more than 80% of cases, intra-abdominal abscesses derive from an intra-abdominal organ, and in most cases they develop after operative procedures. Regarding anatomy, intra-abdominal abscesses can be divided into intra-peritoneal and visceral abscesses and those located in the anterior retroperitoneal space. Despite improvements in ultrasonography, CT is still the most effective method in diagnosis and therapy. Percutaneous ultrasound or CT-guided drainage is a therapy characterized by low procedural morbidity and is successful in 80% of cases if strict criteria are met. Complicated abscesses and those cases in which the underlying disease has to be treated require surgical intervention. Most liver abscesses are treated interventionally; in abscesses of the pancreas or spleen and in Crohn's disease, surgery is necessary. The combination with sufficient antibiotic drug therapy is very important. Specific infectious diseases appearing as intra-abdominal conglomerates (tuberculosis, actinomycosis, amebiasis) lead to a delay in diagnostics because of their scarcity and are characterized by special patho-anatomical, diagnostic and therapeutic features. The crucial thing is to take a specific infection into consideration.