The properties and structural parameters of compact and conventional ring yarns produced at five different twist levels were compared. A modified version of the tracer fiber technique (J. Textile Inst., 43, T60-T66, 1952) combined with the Image Analysis Application Version 3.0 (B.A.R.N. Engineering) was utilized to explore yarn structure. Results obtained from these analyses showed that the high tenacity values of compact yams can be attributed to the higher rate and amplitude of fiber migration in these yarns compared to those in conventional ring yarns. Another important finding was the superiority of compact yarns in terms of tensile properties is less noticeable at higher twist levels and in 50/50 polyester/cotton blend.