During the last decade, there has been a dramatic increase in the use of Section 48. However, apart from this increase in numbers and the presumed clinical benefits Section 48 brings to transferees, to date very little research has been conducted on the overall effect of Section 48. Consequently, a study was conducted to assess the effect of Section 48 on patients transferred from prison to hospital in 1992. The study sample came from lists provided by Great Britain Home Office sources. The study found 377 identifiable transfers made in 1992 under Section 48, and these individuals were assessed with respect to previous convictions, previous custodial sentences, psychiatric history, previous detention under the Mental Health Act of 1983, index offenses, principal victim of the index offense, and diagnosis at time of transfer. Of the overall sample, 90 percent had a previous criminal and/or psychiatric history, but only 5 percent had previously been subject to a Section 48 transfer. Most of those transferred under Section 48 were charged with a violent offense, including 11 percent charged with murder. In cases involving identifiable victims, 35 percent were known to the offender, 22 percent were strangers, and 11 percent were officials such as the police. The Mental Health Act category specified in all cases was mental illness, with 50 percent being diagnosed as schizophrenic. Nearly 60 percent of transfers were requested within 25 days of remand, and the vast majority of cases (78 percent) resulted in conviction. In general, the analysis strongly suggested Section 48 was fulfilling an important role in facilitating the transfer of mentally ill remand prisoners who required hospital treatment. An appendix contains statutory provisions of Section 48. 39 references, 2 notes, and 15 tables