The purposes of this three-phase study were to explicate criteria for patient selection for students' hospital experience, to develop a patient selection instrument and to test its criterion-related validity and inter-rater reliability. In the first phase, 54 experienced nurse educators rated the importance of 63 criteria that may be used in patient selection. The mean ratings of the criteria were used in developing the first draft of the Patient Selection Instrument (PSI) in the second phase of the study. A pilot test of the PSI resulted in revisions. Ninety-four other experienced nurse educators then participated in the third major phase, a methodological study of the PSI. Criterion-related validity (McNemar's x2 = 4.000; p less than 0.05; Kappa = 0.524, se = 0.102, t = 4.918, p = 0.000) and inter-rater reliability (McNemar's x2 = 2.00, p greater than 0.05; Kappa = 0.338, se = 0.180, t = 1.824, p greater than 0.05) were established. A modification resulted in the final version of the PSI. The PSI will be useful to novice nurse educators and as a teaching tool in programs preparing nurse educators.