Organizational learning is fundamental for improving performance within a rapidly changing and competitive business environment. The dissertation develops a model that assesses the impact of organizational learning on performance of architectural design firms. An extensive literature review was realized on organizational learning, performance, and architectural design firms. The impact of organizational learning on performance of the architectural design firms was measured with an instrument. The structured questionnaire includes information about organizational learning constructs namely; learning flows (feed-forward and feedback), learning stocks (learning at individual, project, and firm levels), and performance of the firm. After a pilot study was conducted in Northern Cyprus, the main questionnaire survey was administered to 165 architectural design firms in Turkey. A structural equation model was developed by using Structural Equation Modeling (SEM) to determine how organizational learning can be prioritized in driving performance improvement. The direct effect of .learning at firm level on performance of the firm. was high (.81). The 10 claimed hypotheses were accepted. It was found that there is a high correlation between .learning flows. (.90). The direct effect of .feed-forward on learning at individual level. and .feedback on learning at firm level. is high (.70 and .74 respectively). This research provides reference for architectural design firms on measuring the impact of organizational learning on performance of the firm. The dissertation was concluded with confirming the interrelations of organizational learning constructs and significant impact of organizational learning on performance of the firm.