Drape is one of the most important fabric aesthetic properties. Although there are many studies related to the drape structure of seamless fabrics, knowledge about the drape behavior of seamed fabrics is very limited. This study analyzes the effect of five-thread overlock seams (stitch type 516, seam type Ssa-1) on the drape behavior of heavy weight knit fabrics to provide prediction equations for drape. Results are statistically analyzed. From the regression analysis, the drape coefficients of seamed heavy weight knit fabrics and the rating values obtained from a subjective analyses are predicted with 0.80 and 0.86 correlation coefficients, respectively.