In this article, we examine the use of the key informant methodology by researchers investigating interorganizational relationships. Authors have advocated the use of multiple informants to increase the reliability and validity of informant reports. However, interorganizational research still tends to rely on single informants. We investigated informant selection and obtaining perceptual agreement among multiple informants, two problems that may have inhibited widespread use of multiple informants. We suggest procedures for dealing with those problems and provide an illustrative application of our proposals.