Objective The aim is to summarize the clinical experiences of 435 reverse sural fasciocutaneous flaps, and analyze the risk factors related to the partial necrosis of the flap. Methods Between April 2001 and December 2019, 435 reverse sural fasciocutaneous flaps were employed to reconstruct soft tissue defects over the pretibial, ankle, heel, and foot. The flap viability-related complications (i.e., partial necrosis), and potential risk factors (i.e., patient factors, flap factors and surgical factors) were compared between the survival group and partial necrosis group. Results Among the 435 flaps, 396 flaps survived completely, and 39 flaps (8.97%) exhibited partial necrosis. There were no significant differences in gender, age, soft tissue defect site, etiology, length and width of the adipofascial pedicle, width of the skin island, and pivot point position of the flap between the survival and partial necrosis groups (P > 0.05). The length of the skin island, total length, and LWR (length-width ratio) of the flap in the partial necrosis group were significantly greater than those in the survival group (P < 0.05). The constituent ratio of the top edge of the flap in the 9th zone, the LWR more than 5:1 and the total length more than 20 cm in partial necrosis group were significantly higher than those in the survival group (P < 0.05). Multiple logistics regression analysis results showed that the total length and top edge of the flap were two independently associated risk factors affecting partial necrosis of the flap. Conclusions The top edge of the flap is an essential indicator for predicting the prognosis of the reverse sural fasciocutaneous flap. When the top edge of the flap is in the 9th zone, total length of the flap is more than 20 cm or LWR of the flap more than 5:1, the partial necrosis rate will increase significantly.