Various techniques may be used to repair Achilles tendon ruptures; however, we contend that using the strongest suture with the least amount of suture material is ideal. To compare the strength of 2-0 FiberLoop (Arthrex Inc, Naples, Florida) and #2 Ethibond (Ethicon Inc, Somerville, New Jersey) suture materials in Achilles tendon repairs, 12 Achilles tendons were harvested from cadavers aged 18 to 62 years (median age, 42 years). The tendons were transected and repaired using a modified Krackow suture technique. All of the right limbs were repaired with 2-0 FiberLoop, and the contralateral side was repaired with #2 Ethibond. The specimens were mounted to a materials testing system, and the repairs were pulled to failure in an anatomical direction. The mean +/- SD yield loads of 2-0 FiberLoop and #2 Ethibond were 233 +/- 48 N and 134 +/- 34 N, respectively (P = .002). The mean +/- SD ultimate load of 2-0 FiberLoop was 282 +/- 58 N, and that of #2 Ethibond was 135 +/- 33 N (P < .001). The cross-sectional area of one pass of 2-0 FiberLoop was calculated to be 0.21 mm(2), and one pass of #2 Ethibond was 0.28 mm(2). The smaller-caliber 2-0 FiberLoop was significantly stronger than #2 Ethibond. This study suggests that there is no advantage to using the traditional larger suture material for Achilles tendon repairs; however, further clinical testing is needed to determine the optimal repair technique.