Although there are many distinctions between the male and female skeleton, there is no method that is 100% accurate to determine the sex of someone simply from their bones.  The areas that are most distinctive are the pelvis and the skull.  In addition, male bones are thicker and heavier than female bones.  When comparing the skeletons, one can observe that most female features (with the exception of the pelvis) are smaller than male's.  

Pelvic bone:

• Wider in females to allow for easier childbirth (oval/round shaped)
• The first area one would look at to try to determine the sex
• Male pelvis is heavier and narrower (heart shaped)
• Female pelvis less massive and more delicate
• Woman of short stature tend to have broader pelvises
• In the 4th month of fetal development, characteristics of the pelvic bone in an individual begin to form
• In the female, the upper end of the pelvis is tilted forward, while in males it is relatively vertical 

Skull (head features):

• Female skull retains certain pre-pubescent attributes
• Male skull becomes more rough at sites of muscle attachment
• The man's cranial mass is more blocky and massive - female's cranial mass is rounder at the top 
• The super orbital margin (area above the eyes) is sharper in females - in males it is rather round and dull
• The cheek bone is more pronounced on the male skull 
• Lower jaw is more squared for a male whereas the female's jaw is rounder
• Men's teeth tend to be larger  
• Male skull tends to be heavier
• Women's eyes are further set apart than men's 

                              Male                                             Female

Miscellaneous facts:

• Women have a knock-kneed effect in their thighs and lower legs
• Men's legs form parallel lines
• Increased level's of testosterone during puberty in males leads to the development of greater height, more rugged characteristics, and narrower pelvic width 
• A man's skeleton has broader shoulders and a longer ribcage
• Typical male features are often more pronounced and marked than the same features in females 
• It is very difficult to differentiate between male and female skeleton's because there are overlaps of male and female features 
• Archeologists have had a difficult time determining from skeleton x-rays whether King Tut was actually male or female