The authors emphasize the importance of the admission process in the overall course of hospitalization. Reviewing the literature, demographic, social, symptom, interpersonal, organizational, and attitudinal factors all seem to influence both who becomes hospitalized and where. In spite of this there have been few systematic attempts to establish rational admission criteria. As a result, this lack has oftentimes led to inappropriate admissions on the one hand and to underutilization of hospitalization on the other. To help offset this difficulty a list of valid reasons for hospitalization is proposed. It is pointed out, however, that although such criteria are useful in determining who should be admitted, it is of limited value in deciding where the patient should be hospitalized. In matching individual patients with particular types of hospitals it is useful to consider certain parameters. More specifically, the hospital variables are: a) the average length of stay; b) individualvs.milieu orientations; and c) active treatmentvs.custodial care. The patient variables are: a) the duration of the presenting problem; b) degree of psychosocial problems; and c) the patient's failure to respond to a hospital's treatment program. Utilizing these six variables, the authors present explicit guidelines for matching particular patients with particular hospitals.Finally, certain general theoretical principles and practical techniques are suggested to improve the admission process. A two-stage admission process is suggested, which includes: a) preadmission screening; and b) the admission work-up. The goals of the former stage are to determine if the patient belongs in that particular hospital, to obtain information, to instill a sense of hope, to collect data, and to set a proper tone. The goals of the latter stage are to acquire a complete history and to acclimate the patient to the treatment facility. It is pointed out that the way in which the total admission procedure is executed can have a profound effect on the subsequent course of hospitalization.