Anterior cruciate ligament (ACL) injury-associated meniscus lesions increase the risk of ACL graft failure and induce poor functional outcomes and development of knee osteoarthritis. Damage to both the anterior cruciate ligament (ACL) and the menisci furthermore compromises knee joint stability and affects joint laxity to a greater extent than an isolated ACL tear. As meniscal tears are reported in up to two patients undergoing an ACL reconstruction out of three, they should be systematically looked for and considered in the treatment decision process. This systematic analysis of structural damage at the time of the ACL injury should also include the latest types of meniscus injuries like ramp or root tears or meniscus instabilities which are increasingly being taken into consideration. The aim of the present chapter is to provide an overview of the current understanding of ACL-associated meniscus lesions and discuss the current recommendations and limitations in their diagnosis and treatment.