Background and Purpose-By 2010 there had been 14 published trials of surgery for intracerebral hemorrhage reported in systematic reviews or to the authors, but the role and timing of operative intervention remain controversial and the practice continues to be haphazard. This study attempted to obtain individual patient data from each of the 13 studies published since 1985 to better define groups of patients that might benefit from surgery. Methods-Authors of identified published articles were approached by mail, e-mail, and at conferences and invited to take part in the study. Data were obtained from 8 studies (2186 cases). Individual patient data included patient's age, Glasgow Coma Score at presentation, volume and site of hematoma, presence of intraventricular hemorrhage, method of evacuation, time to randomization, and outcome. Results-Meta-analysis indicated that there was improved outcome with surgery if it was undertaken within 8 hours of ictus (P = 0.003), or the volume of the hematoma was 20 to 50 mL (P = 0.004), or the Glasgow Coma Score was between 9 and 12 (P = 0.0009), or the patient was aged between 50 and 69 years (P = 0.01). In addition, there was some evidence that more superficial hematomas with no intraventricular hemorrhage might also benefit (P = 0.09). Conclusions-There is evidence that surgery is of benefit if undertaken early before the patient deteriorates. This work identifies areas for further research. Ongoing studies in subgroups of patients such as the Surgical Trial in Lobar Intracerebral Hemorrhage (STICH II) will confirm whether these interpretations can be replicated. (Stroke. 2012; 43: 1496-1504.)