If you're an active Adsense publisher, I'm sure you have seen irrelevant Adsense ads on your site. Right? I've experienced them too.
Not only these ads do not relate to your website content, they will not get clicked as well.
Recently I've figured out several ways how to solve this problem.
1- Try adding META tags to your web page. The most important tags are TITLE, DESCRIPTION and KEYWORDS.
2- Rename your html file. Don't use a generic name. Instead, use your keyword(s) as your file name. For example, if the page is about making money with Adsense, simply name it make-money-with-adsense.htm.
3- Try refreshing your page again and again until you see relevant ads displayed. You can refresh the page by clicking on the refresh button, or pressing F5 key on your keyboard.
4- If any of the above tricks do not work, you can send an email to Google Adsense Support telling them about the problem. Don't hesitate. Their support team will reply to your email shortly.
I've experienced this problem with several sites of mine, and it was solved 2-3 days after contacting Google Adsense team.
Mohd Fairuz maintains a website called AdSense Insider Secrets. On his site, he shares with his visitors free tips, secrets & strategies how he managed to boost his Google AdSense earnings by 700%.
Go to his website, and get the tips, free of charge at: http://www.adsense-insider-secrets.com