Thrombocytopenia is frequently encountered in the ICU. It is important to have an understanding of the common and important causes of TP as well as to have a simple framework to approach this problem. A simple approach is to identify if TP is expected or unexpected and work through the management that way. Platelet transfusions or repeating the FBC is not always the right approach. Heparin induced thrombocytopenia is frequently considered as the cause of TP. This leads to excessive HITS screen being ordered and risks false positive results.