Ubiquitous computing is a growing technology as an aspect of both knowledge creating and information dissemination. Context aware systems are a component of ubiquitous computing. Such systems can sense their physical environment and adopt their behavior accordingly [1, 2]. Context aware systems are concerned with acquisition of context gathered from sensors and make their activity to adopt their behavior based on the recognized context using reasoning technique. The objective of this systematic review is to analyze the various reasoning techniques in pervasive environment and to identify the research gap. Systematic method (SLR) has been chosen to investigate relevant research work from various electronic data sources. The ubiquitous computing environment requires reasoning technique which provides more efficient solutions that can deal with uncertainty and in completeness. Multiple reasoning techniques are more suitable for the hybrid systems. The combinations of technique are complementary to each other. It is difficult to combine the multiple techniques for the hybrid systems. A more efficient approach need to be identified for better reasoning. In our study, we identified 14 context management systems in which reasoning has been used to deduce new knowledge based on the available context data. Most commonly used reasoning methods for a context aware system was compared and effective reasoning approach was identified by combining case based and rule based reasoning © 2016, International Journal of Pharmacy and Technology. All rights reserved.