Children with sickle cell disease (SCD) are at risk for acute vasoocclusive crises, the most frequent of which are pain crises. The usual treatment for pain crises, intravenous (IV) fluids and pain medicine, has changed little over the past three decades. The purpose of this study was to determine the safety and efficacy of intravenous magnesium in shortening the duration of a pain crisis and to determine the health-related quality of life and short term outcomes of children treated with intravenous magnesium during an acute pain crisis. This was a multi-center, randomized, double-blind, placebo controlled trial. Patients were randomized to receive either the study drug or placebo every eight hours for a total of six doses, or until discharge, whichever occurred first. Patients were followed up by phone one week after discharge to assess rehospitalization rates, and returned to the sickle cell clinic for follow up within 3 months after discharge. Enrollment began in December 2010 and concluded Dec 2013. This project was co-funded by NICHD and NHLBI. Findings were published in Blood on July 31, 2015. The public use dataset is available on this website.