It is said that Thailand is generally safe for tourists but that is really up in the air. Perhaps it is if you know all the tricks and are traveling in a group but traveling alone is not a great idea, especially if you are a female. Even females traveling together is not safe in some places. It's important to know the areas and which are safe and which are not. Take it from those who have gone before you and be wise.
Places should be avoided after dark for women and that includes fun attractions like Sunset Beach and even Full Moon Party which are on Koh Paghang. Women should be wary of taking taxis alone or even being on the streets after dark in a big town. Thailand is safe to an extent but only if you use caution and know where not to go. Remote areas are never good for women to travel in alone, night or day. And whatever you do, if you are a femaile...don't touch a Monk!