Objectives: To analyze the resources available for urgent transfer of patients from regional hospitals and the organization of those resources, and to determine the variables related to the presence or absence of resources. Methods: Descriptive, analytical study of 12 hospitals chosen by stepwise nonprobablistic sampling. We determined the human resources available for patient transfers, the organization of those resources, distance to the referral hospital, the number of urgencies attended, the number of transfers accomplished, and the time spent in each transfer. Results: We detected excessive variation between regional hospitals with regard to the resources available to them, the volume of urgencies attended, and size. Outside suppliers of transport services were always used by 8.3% of the hospitals, whereas internal resources were used by 58.3%. The remaining 33.3% used a combination of their own services and outside suppliers. The hospitals that had their own staff for transferring patients used different models to organize them. Some used on-call doctors and nurses, who were located as needed, whereas others used staff in the course of their regular duties. The availability or not of human resources was influenced by hospital size and distance from the referral hospital. Conclusions: Hospitals do not organize their human resources for patient transfers following similar models, creating the impression that a model is lacking. The variability cannot be explained by differences in resources and volume of urgencies attended in the hospitals. The use of on-call personnel who are located to assist with urgent patient transfers seems to be related to hospital size and distance from the referral hospital, but not by the average time the transfer takes, the volume of urgencies attended, or even the number of transfers required. [Emergencias 2008;20:245-250]