Eighty‐nine journals were identified as potentially important journals supporting biotechnology R&D through the analysis of journal citation networks (1991 Journal Citation Reports). Twelve research areas emerged: one set of linked intercitation clusters representing the central areas of concern—biotechnology, microbiology, molecular genetics, food science and technology, and plant science. Organic chemistry and natural products research comprised a linked pair, while the remainder, horticulture, pharmaceutical science, chemical engineering, biosensors, and water research remained single clusters. Mapping and clustering of cocitation data (1988–1992 SCISEARCH) displayed a similar structure, with the clusters arranged along a basic (natural science)—applied research (engineering) continuum. A subject indexing profile analysis (Biotechnology Abstracts, 1990–1992) showed that journals in pharmaceutical science, organic chemistry, and natural products rarely if ever published biotechnology‐relevant research. In a productivity analysis, the two top categories (70% coverage—12 titles; 30%–69% coverage—14 titles) included 10 journals not classed as biotechnology by Journal Citation Reports. One of these, Plant Cell Reports (88% coverage), has not been listed as a biotechnology journal in any previous core lists. This database filtering approach, combining citation, indexing, and productivity analyses, is an effective tool for identifying important non‐core journals supporting multidisciplinary R&D. © 1995 John Wiley & Sons, Inc.