One part of the psychometric evaluation of the Patient Intensity for Nursing Index (PINI), a new measure of nursing intensity, is reported. The PINI has four interrelated components: (a) severity of illness, (b) dependency, (c) complexity of care, and (d) time. Taken together, the 10 items that make up these four components comprise the multidimensional construct of nursing intensity. Using the factor analytic approach and a model specification search, the measurement model for the Patient Intensity for Nursing Index was identified. The structure consists of Dependency, Severity, and Complexity with time (hours of nursing care) loading on each factor. When results were cross-validated using data from four other hospitals, support emerged for a consistent pattern of factor loadings. The loadings themselves, however, are only partially invariant. Further examination of the relationship between severity and time is suggested and areas for future research are identified.