This paper investigates the semantic search performance of search engines. Initially, three keyword-based search engines (Google, Yahoo and Msn) and a semantic search engine (Hakia) were selected. Then, ten queries, from various topics, and four phrases, having different syntax but similar meanings, were determined. After each query was run on each search engine; and each phrase containing a query was run on the semantic search engine, the first twenty documents on each retrieval output was classified as being "relevant" or "nonrelevant". Afterwards, precision and normalized recall ratios were calculated at various cut-off points to evaluate keyword-based search engines and the semantic search engine. Overall, Yahoo showed the best performance in terms of precision ratio, whereas Google turned-out to be the best search engine in terms of normalized recall ratio. However, it was found that semantic search performance of search engines was low for both keyword-based search engines and the semantic search engine.