A new Swedish leadership theory of "leadership intelligence" (Ronthy, 2006; 2013) is characterized by a work integrated learning approach. This theory arose from analysis of the experiences of managers trained in performance appraisals, and describes the balance between being a leader and being a manager. A leader develops and uses, in an integrative good balance, leadership intelligence, which comprises emotional intelligence, rational intelligence and spiritual intelligence. The aim of this study was to further develop the Leadership Intelligence Questionnaire (LIQ) created by Ronthy (which has been developed to measure leadership intelligence), and to examine its reliability. Over 400 leaders, aged 21 to 69 years completed the 71-item LIQ. A shorter, 32-item version of the LIQ was developed by confirmatory factor analysis thorough excluding psychometrically "poor" items. The internal consistency measured by Cronbach’s alpha was high (> .80), and we conclude that leadership intelligence may be reliably measured with both versions of the questionnaire. Future studies should examine the internal and external validity of the LIQ before its introduction into education or into managerial practice.