I am currently running PPC campaings on Google and Yahoo. I have recently succeeded in tracking both of them with analytics but the result aren't similar. More specifically in Google Adwords i have a number of visits (let's say 300), while in analytics this number is smaller (like 288). The same happens with yahoo, but the difference is even bigger.

Can someone explain why this happens and what can i do to get same result from both sources?

Google Analytics is far from perfect. Many people report inconsistincies between analytics and adwords stats. Your AdWords stats are likely very accurate since you are paying for those clicks. Meanwhile, since Google Analytics is a free service, Google may not care so much if it's inconsistent.

Yeh some time analytical tool gives you error. So you have to do some extra works for your analytic for your site. Same thing happen with me.

They report different things. Google answers at this question here: http://adwords.google.com/support/bi...n&answer=55610