This paper presents a systems-based appraisal methodology that has been designed specifically to consider the effectiveness of Integrated Coastal Zone Management (ICZM) initiatives. Since ICZM is defined in terms of achieving sustainable development, any such initiative must therefore be capable of meeting the multiple and often conflicting objectives inherent in this ubiquitous concept. The methodology outlined here is designed to critically review ICZM in order to pinpoint areas of management weakness and determine the likely ‘success’ of the process. It represents an example of a management system, incorporates both qualitative and quantitative information, and is proposed as a ‘Coastal Sustainability Standard’ (CoSS). Initial field testing of the methodology has proved successful and shown that the approach holds some efficacy as a means of assessment.