Misdiagnosis can be medical malpractice in some cases, but not in others. There is more required than simply showing that your doctor misdiagnosed your condition in order to have a medical malpractice claim. In order to prove medical malpractice, you must prove that negligence caused your misdiagnosis and resulting injuries. So a misdiagnosis is only considered medical malpractice if negligence was involved and an injury occurred as a result.