The World Wide Web is an information system of interlinked hypertext documents that arernaccessed via the Internet. A search engine is a document retrieval system design to findrninformation stored in a computer system, such as on the WWW. With the exponential growthrnin web content, the answers provided by traditional search engines by query specificrnkeywords to content has resulted in high recall and low precision. Many queries processed onrnthe World Wide Web do not return the desired results because they fail to take into accountrnthe context of the query and information about userâ€™s situation and preferences. Some searchrnengine now has semantic functionality, can understand data context, but it is limited to onlyrnthe context of the query.rnContext-awareness refers to the capability of a software application to provide services torntheir users based on the userâ€™s current context. As such, the objective of this thesis is tornpresent context aware semantic search engines for smart phones. We present the architecturernof context aware semantic search engines on the top of semantic web. Ontology basedrncontext modeling is used to represent user contexts. The userâ€™s query history and submittedrnquery is also analyzed to identify the concept of the search. Prototype of the system is alsorndeveloped to demonstrate and test applicability and effectiveness of the proposed approach.rnTo evaluate the effectiveness of our approach precision measures were conducted on top 15rnretrieved documents. The experimental results showed 71.7 % precision which is higher thanrnkeyword base search results on the same dataset which is 41.18 % precision.rnKeywords Semantic Search; Context aware Search; Search engine; Semantic web.