Background: A number of ocular biometric parameters, iris hiotologic and anatomic characters have been suggested as inciting factors for converting patients with narrow angle to angle-closure glaucoma. This study was conducted to determine if there was any goniscopic difference between patients with acute angle-closure glaucoma (AACG) and chronic angle-closure glaucoma (CACG). Methods: The study is a retrospective analysis of the charts of 97 patients with asymmetric CACG and 15 patients with unilateral AACG. The age, sex, type of glaucoma, gonioscopic findings and optic nerve head cup/disc ratio were recorded for all patients. Dynamic gonioscopy and Spaeth’s convention were used to grade the drainage angle. The eyes with AACG or more optic nerve damage in CACG groups were considered as involved eye, and the contralateral eyes in the AACG and CACG groups were considered as noninvolved and less-involved, respectively. Results: There was no significant difference between patients with AACG and CACG in terms of age, gender, refraction, and laterality of the involved eyes. In intragroup analysis, no significant difference was observed for distribution of iris attachment, irido-corneal angle, iris configuration, or trabecular pigmentation. In intergroup analysis, the superior iris was attached more anterior in the involved eyes of AACG compared to that in CACG (P=0.007). Moreover, the iris root attachment was also more anterior in both the superior (P=0.001) and inferior (P=0.002) angles of the noninvolved eyes of AACG vs. than those in the less-involved eyes of CACG group. Conclusion: The findings of the study indicate that there is no significant difference between the eyes with AACG or CACG in terms of goniscopic findings. However, the superior iris attachment was located more anterior in eyes with AACG compared to that in eyes with CACG.