In order to determine the possible effects of diabetes, we aimed to investigate the expression of extracellular matrix proteins in the theca and granulosa layers in different follicular stages.Thirty-two adult Wistar albino male rats were divided into 4 groups as control and sampled groups. Four, eight and twelve weeks after inducing diabetes with an intraperitoneal injection of streptozotocin (40 mg/kg), the expressions of laminin, type IV collagen and α3β1 integrin in ovarian tissues were evaluated by immunohistochemical method.In our study, in the first month of diabetes, a significant increase was observed in laminin, type IV collagen and α3β1 integrin expressions in all follicle types compared to the control group in both the theca and granulosa layers. Laminin and type IV collagen immunoreactivity tended to increase in D2 and D3 groups also. Integrin expression did not change in the newly formed follicles in the D2 and D3 groups, however, it tended to change and increase in the developing follicles.The changes in the expression of laminin, type IV collagen and α3β1 integrin, which are the extracellular matrix proteins in the follicle, along with diabetes, show that diabetes plays a role in the regulation of follicular development (Tab. 4, Fig. 36, Ref. 29).