The success rate of cardiopulmonary resuscitation (CPR) may differ from institution to institution, even within different sites in the same institution. A variety of factors may influence the outcome. In this study, we assessed the adequacy of CPR attempts guided by the current standards and aimed to define the factors influencing the outcome following in-hospital cardiac arrest. One hundred and thirty-four patients who required CPR were studied prospectively. Different variables for the CPR performance were recorded using forms designed for this study in the tight of the guidelines. In these CPR forms various data including the demographics, history, monitoring, number, composition and experience of the anaesthesiologists, the site of CPR, time of day, the delay before onset of CPR, tracheal intubation, duration of arrest, initial rhythm in ECG monitored patients, management of CPR, drug administration and reversible causes of cardiac arrest were recorded. Our rates of immediate survival, survival at 24h and survival to discharge 49.3%, 28.5% and 13.4%, respectively. The extent of monitoring prior to arrest, the attendance of one or more experienced anesthesiologists in the CPR team, CPR during office hours, CPR in ICU or operating room, early initiation of CPR and tracheal intubation prior to arrest were found as the factors increasing discharge survival. We conclude that early initiation of CPR with an experienced team in a well-equipped hospital sites increases the discharge survival rate following cardiac arrest. (c) 2005 Elsevier Ireland Ltd. All rights reserved.