Purpose: While the strategic management literature extols the virtues of engaging in strategic planning for superior performance, how a dynamic strategic planning capability can be developed remains underexplored; a knowledge void addressed by the paper through applying knowledge-based theory. Design/methodology/approach: A mail survey was sent to high technology firms randomly sampled from the Kompass Directory of UK businesses. Firms were sampled at the SBU level, given the focus on strategic planning capability. Findings: An organization’s strategic planning capability derives from extensive information distribution and organizational memory. While learning values is non-significant, symbolic information use degrades the development of a strategic planning capability. Research limitations/implications: By investigating the contributory activities that lead to strategic planning capability development, the findings establish how strategic planning materializes in organizations. Further, the differential effects found for knowledge management activities on strategic planning capability development extend empirical studies that suggest knowledge is always a central tenet of strategic planning. Practical implications: A set of key knowledge activities is identified that managers must address for strategic planning capability development: strategic planning routines and values of search, analysis and assessment should be appropriately informed by investments in knowledge dissemination and memory on a continual basis. Meanwhile, information misuse compromises strategic planning capabilities, and managers must protect against out-of-context or manipulated information from infiltrating into organizational memory. Originality/value: Despite the advent of the knowledge-based theory and its core premise that capabilities derive from knowledge management activities, little research has been conducted into demonstrating the knowledge-based antecedents of a strategic planning capability.