Purpose. To compare the results of extracorporeal shock wave therapy (ESWT) for insertional Achilles tendinopathy (IAT) with or without Haglund's deformity. Methods. Between September 2014 and May 2015, all patients who underwent ESWT were retrospectively enrolled in this study. A total of 67 patients were available for follow-up and assigned into nondeformtiy group (n = 37) and deformtiy group (n = 30). Clinical outcomes were evaluated by VISA-A Score and 6-point Likert scale. Results. The VISA-A score increased in both groups, from 49.57 ± 9.98 at baseline to 83.86 ± 8.59 at 14.5 ± 7.2 months after treatment in nondeformity group (P < 0.001) and from 48.70 ± 9.38 at baseline to 67.78 ± 11.35 at 15.3 ± 6.7 months after treatment in deformity group (P < 0.001). However, there was a greater improvement in VISA-A Score for the nondeformity group compared with deformity group (P = 0.005). For the 6-point Likert scale, there were decreases from 3.92 ± 0.80 at baseline to 1.57 ± 0.73 at the follow-up time point in nondeformity group (P < 0.001) and from 4.0 ± 0.76 at baseline to 2.37 ± 1.03 at the follow-up time point in deformity group (P < 0.001). There was no significant difference in improvement of the 6-point Likert scale between both groups (P = 0.062). Conclusions. ESWT resulted in greater clinical outcomes in patients without Haglund's deformity compared with patients with Haglund's deformity.