Background <p>Viability of fasciocutaneous flaps in distal lower extremity is affected by chronic venous insufficiency. The aim of this experimental study was to investigate how fasciocutaneous flaps in distal lower extremity were affected by the etiology and the level of chronic venous insufficiency.</p> Methods <p>24 rats were divided into three groups of eight rats each. In the first group, a fasciocutaneous flap was performed on the left hind extremity without creating venous insufficiency. In the second group, the same flap performed three weeks after chronic venous insufficiency was created by ligation. In the third group, the same flap performed three weeks after the creation of an arteriovenous fistula between the femoral artery and vein. One week after flap elevation, the flaps were photographed and the rats were sacrificed and specimens were taken.</p> Results <p>Chronic venous insufficiency caused a statistically significant increase in flap necrosis rates (<i>p</i> &lt; 0.05). While the rate of flap necrosis was 64.1% in the ligation group, the rate of flap necrosis was 53.49% in the fistula group. In the control group, this rate was 39.09%.</p> Conclusions <p>The presence of venous insufficiency in patients planned for lower extremity reconstruction may adversely affect the operation plan. In the rat model, it was thought that the anatomical level of venous pathology in chronic venous insufficiency may have a greater effect on fasciocutaneous flap viability than the effect of increased intravenous pressure.</p> <p>Level of Evidence: Not gradable.</p>