All your data that is stored on Yandex services is associated with your account. When you delete your account, you also delete all your data on all the services — emails in Yandex.Mail, pictures in Yandex.Fotki, and so on.
If you used Yandex.Money, Yandex.Direct or Yandex.Mail for domains, you cannot delete your account permanently: your data on other services will be deleted and your username will be blocked. The account cannot be used, and the username cannot be registered again.
To delete your account, go to the link Delete account on the Personal information page.
Do not rush to delete your account completely in order to solve a problem you are having on one of the services. You can always contact Support.
After deleting your account, you can't open a new account with the same username for six months. This means that no one can take the username of a deleted account right away after it was deleted. Usernames are unblocked automatically, so we do can not tell you exactly when it will happen, and we cannot change this date.
We do not have the technical capability to find out who deleted your account and under what circumstances. When you click Delete account, the data is erased immediately and a new account with the same username cannot be registered within 6 months.
If your account was deleted without your knowledge, it means that someone found out your password or the answer to your security question. Please familiarize yourself with our recommendations in the section Protecting your account, to prevent such problems in the future.