The results overwhelmingly support the view that the coefficient of friction is not a material constant of the sutures but a function of several variables, including applied tension, suture construction and suture material. The coefficient of friction decreased with an increase in applied tension with the rate of change depending upon the suture material. Prolene and Ethilon had the highest frictional values among all sutures at low tension, but dropped to a position of lowest values at high tension. On an average, braided sutures gave higher frictional values than did the monofilament sutures. Sutures with special surface coatings (silicone or Teflon) generally gave lower values than did the sutures without any such coatings. Similar results were reported in other studies on coated materials. The differences in frictional profiles are governed by the differences in the viscoelastic nature of the suture materials. The unusual traces produced by Prolene were considered as being due to its high degree of stretch and elasticity. Others similarly found that Prolene behaved peculiarly due to a high degree of stretch. Finally, coefficient of friction is an important property of suture materials as it is expected to have a direct bearing on the security of knots. A careful study of this parameter under a variety of clinical conditions is essential to gain an understanding of the behavior of surgical knots in clinical practice. The present study gives detailed information on the frictional behavior of various types of surgical suture materials.