ACL  tears  are the  most  widespread  lesions  among  isolated  trauma  of knee  ligaments  that  require  early  surgical treatment especially in young active patients. There  are various ACL reconstruction techniques where femur and tibia tunnels are formed and graft is fixed by cannulated interference screws. One of the possible complications is the formation of a postoperative soft tissue cyst in the projection of tibial tunnel.  The nature  as well as mechanism of cyst formation  is still unclear.A relevant  clinical case of cyst formation  in a patient five years after ACL grating  is described  in this publication. MRI findings demonstrated that  the origin of the cyst was hole of the tibial interference screw.Conclusion. The authors  observed that  synovial cyst was formed due to use of cannulated interference screws where synovial  fluid was leaking  from joint  cavity  through screw holes. Cystectomy and  autografting of tibial  bone tunnel allowed to reduce such complication.