Objective: To document bioinformatics tasks currently performed by researchers in genomics and proteomics in an effort to recognize unmet informatics needs and challenges, identify system features that would enhance the performance of those tasks, and inform the development of new bioinformatics tools. Design: A cross-sectional study of bioinformatics tasks performed by OHSU investigators involved in genomics and proteomics research was conducted using task analysis techniques. Results: Four major categories emergedfrom 22 bioinformatics tasks reported by 6 research laboratories. These were: 1) gene analysis, 2) protein analysis, 3) biostatistical analysis, and 4) literature searching. Analysis of the data also raised the following challenging issues: 1) lack of procedural documentation, 2) use of home-grown strategies to accomplish goals, 3) individual needs and preferences, and 4) lack of awareness of existing bioinformatics tools. Conclusion: Task analysis was effective at documenting bioinformatics tasks performed by researchers in the fields of genomics andproteomics, at identifying potentially desirable system features and useful bioinformatics tools, and at providing a better understanding of some of the unmet needs and challenges faced by these researchers.