Previous research concerning relevant source characteristics has often confounded source expertise and source experience. This study examines whether these two source attributes have differential effects on consumer attitudes. A laboratory study based on a 2 (high/low expertise) 2 (high/low experience) factorial design was conducted. The results indicate that: consumers can distinguish between endorser expertise and experience; information communicated by an endorser high in expertise as compared to one low in expertise leads to more positive attitudes toward the endorser and the advertisement; and even though consumers can discriminate between low and high experience endorsers, no effects on attitudes toward the endorser and the advertisement can be shown. Since it seems to be more difficult for consumers to assess experience than expertise and consumers seem to discount an experienced source as being too subjective and/or not knowledgeable enough, choosing an expert endorser might be more effective for certain target markets.