This paper describes a new approach to corporate technological performance assessment, based on patent citation analysis. We define this technological performance assessment as “the use of patent counting, clustering, and citation analysis in the evaluation of corporate, industry-wide, and national technological activity.” After reviewing the state-of-the-art of patent citation analysis, we discuss five different ways of formatting large-scale patent data for performance assessment. These formats are: 1) patent lists, with citing and cited patents, 2) laboratory impact tables, 3) corporate technology profiles, 4) corporate linkage maps, and 5) patent citation network diagrams. The technological performance assessements to which these different formats may be applied include: 1) corporate activity measurement and competitor analysis, 2) anti-trust, 3) technological forecasting and long-range planning, 4) R&D productivity measurement, 5) company linkages and corporate technological integration, 6) strategic targeting, especially for merger and acquisition purposes, 7) international trade and technology flow analysis, and 8) market and license identification.