Examine the ticket's surface. A true Ticketmaster ticket has thin lamination that catches the light, something most fakes do not have.
Check the tickets against comparable tickets online to see if the pricing is legitimate. Some scammers may take legitimate tickets for bad seats and alter the section and row to make someone thinking he or she is getting a deal. If you know tickets in that section are selling for much higher than the face value you're seeing, don't buy the tickets.
Hold the ticket up in front of a strong light or even sunlight. The white Ticketmaster ticket should glow blue.
Check the ticket's general information to see if it's accurate. Check the performer, date and time to see if they all line up correctly.
Compare the ticket to an old Ticketmaster stub. Note changes in detail, such as a different font or strange type styles. You may even notice a random typo. These are warning signs that this ticket is a forgery.