Keith Boardman has made a variety of important contributions on the biochemistry, development and molecular architecture of chloroplasts. He was the first to achieve physical separation of the two photochemical systems of photosynthesis and has added greatly to knowledge of their components and function. He has also made important studies on the characteristics of bundle chloroplasts of C₄ plants and the comparative photosynthesis of sun and shade plants. He also directed his attention to the efficiency of solar energy conversion by photosynthesis in plants and the potential of biomass for fuel production.

He was Chief Research Scientist in the Division of Plant Industry of the Commonwealth Scientific and Industrial Research Organisation (CSIRO) before joining the Executive Board of CSIRO, serving as Chairman/Chief Executive. Since retirement, his main scientific interests have been an involvement in the Cooperative Research Centres Programme and National Landcare Programme of Australia, science policy for the Australian Academy of Science and chairing the review of the Institute of Advanced Studies of the Australian National University.