A deficient structure can be defined as one which does not fulfil its intended function. This deficiency appears in the form of distress in its components. Various reasons which lead to the necessity of rehabilitation in any structure are described in this paper. Also described are various steps which are involved in a general rehabllitation programme. Most Important of these steps consists of analysis of symptoms and diagnosis. To facilitate a quick Identification, various known symptoms for all conventional construction materials are tabulated and the possible sources of trouble ake indicated. The Information for concrete structures is extracted from a publication by R.F. Warner [1]. A similar compilation for steel, wood and masonry is freshly prepared.