The aim of this article is to evaluate and classify pathogenetic origins based on morphologic reproliferative patterns in patients who underwent pterygium excision with a conjunctival autograft. In this retrospective, observational case series, a total of 116 eyes of 116 patients with pterygium who underwent pterygium excision with a conjunctival autograft between February 2009 and May 2011 were reviewed. Using consecutively recorded photographs, we evaluated preoperative morphologic severity, postoperative complications, recurrences, and growth patterns. The regrowth of fibrovascular tissue was observed in 14 of our study cases (12.1%). Of these, 5 cases (4.3%) showed clinically significant recurrences. We observed 3 different morphologic patterns of recurrence: regrowth over the epithelial defect; transformation of the conjunctival graft into the pterygial tissue; and regrowth from unexcised pterygial tissue. Each recurrence pattern showed characteristic fibrovascular growth, the origin of this regrowth, and grade of severity. In 25 cases (21.6%), postoperative complications were observed. Of the analyzed variables, age <40 years (P = 0.019; odds ratio [OR], 5.82; 95% confidence interval [CI], 1.34-25.28) and the presence of postoperative complications (P = 0.008; OR, 6.32; 95% CI, 1.62-24.58) were statistically significant in multivariate analyses using logistic regression. The use of conjunctival autografts for pterygium surgery is effective, but recurrences are observed in some cases exhibiting unique pathogenic patterns according to their origin. A complete understanding of the pathogenesis of these lesions based on their morphologic regrowth pattern will help to prevent recurrences in patients who undergo pterygium surgery.