We undertook a prospective study of 125 intrahospital patient transports from the ICU in an attempt to identify any factors that could influence the occurrence of mishaps. One third of the transports sustained at least one mishap. Therapeutic intervention scoring system class IV transports had the highest rate of mishaps (35%). We found no relationship of occurrence of mishaps to severity of illness (Acute Physiology and Chronic Health Evaluation, APACHE II), number of lines, monitoring and support modalities, and time out of the ICU. Transports for elective procedures had more mishaps (60%) than occurred for emergencies (40%). Most mishaps occurred either during the procedure, on transports to CT scan, or while waiting at the destination. The numbers and types of escorts as defined by our ICU policy and physician attendance on transport did not clearly reduce mishap risk. Morbidity and mortality were not affected by mishaps. Although certain trends did emerge, no clearly defined predictive factor could be identified. Further study into transport mishaps is warranted.