Theoretical writings on trust and interorganizational collaboration have neglected the measurement aspects of trust. Defining trust as an individual's behavioral reliance on another person under a condition of risk, we developed and tested the construct validity of a questionnaire measure that assessed trust between the individuals who provide the linking mechanism across organizational boundaries, namely, boundary role persons (BRPs). The measure's hypothesized multidimensionality was examined. The measure was tested in relation to a nomological network comprised of individual-level correlates based on Ajzen and Fishbein's (1980) theory of reasoned action and dyad-level correlates regarding the longevity of the relationship between BRPs, the anticipated future longevity of their relationship, and their ability to manage conflict. Survey and archival data were used. Support for the measure's construct validity came from individual-level confirmatory factor analyses. Further support came from analyses of individual-level and dyad-level correlates. Implications for the measure's use in future theory testing on BRP trust and interorganizational collaboration are discussed. (C) 1995 Academic Press, Inc