Treatment modalities developed in intensive care units in recent years have led to the reduction of premature deaths from multiple organ failure (MOF). In patients with late period of MOF the Chronic Critical Patient symptoms caused by the imbalance between Systemic Inflammatory Response syndrome and Compensatory Anti-inflammatory Response syndrome are observed frequently. Persistent Inflammation, Immunosuppression and Catabolism syndrome (PICS) have been defined in today's intensive care practice as a catabolic patient group with recurrent episodes of infection with insuppressible inflammatory process. PICS should all be taken into consideration in the presence of persistent inflammation (C-reactive protein >150 mu gr/dL), retinol binding protein <10 mu gr/dL, lymphopenia (<800/mm(3)), catabolic status (albumin <3 g/dL, creatinine elevation index <80%, >10% weight loss or body mass index <18 occurred during intensive care unit stays) and inflammatory processes [interleukin (IL)-6, IL-10, IL-1ra, tumor necrosis factor receptor 1, procalcitonin] in more than 10 days of intensive care stay. It is aimed to avoid recurrent inflammation and to treat specific components of the syndrome by pharmacotherapy, physiotherapy and nutritional support. In this review, we aimed to recognize the phenomenon of PICS in daily intensive care practice, to understand the development mechanisms and to emphasize the importance of therapeutic research.