The insertions of the menisci to the tibia are the most important restraints to extrusion from the knee joint, and are vital for the functional integrity of the menisci. The aim of the present study was to determine variations of tibial insertions of the medial menisci (MM) in newborn cadavers macroscopically and in adults by arthroscopy. Neonatal part of this study was performed on 40 knee joints of 20 Caucasian neonatal cadavers. Adult part was performed on 41 Caucasian adults, whose ages were between 17 and 66 unilaterally by arthroscopy. In neonatal cadavers, according to its insertion, anterior horn of MM was classified in five groups and type 4, in which it was inserted to the transverse ligament, was determined the most frequent one (45%) and posterior horn of MM was classified in three groups and type 3, in which it was inserted to both the posterior intercondylar area of tibia and medial tubercle of intercondylar eminence was determined the most frequent one (50%). In adults, anterior end of MM was most frequently inserted to both anterior intercondylar area of tibia and transverse ligament (76%) and posterior horn of MM was inserted to the posterior intercondylar area of tibia in all of them. This study provides comparative information about insertion of the MM for neonatals and adults, not to evaluate the variants of the insertion of the MM as a tear of the anterior cruciate ligament or a meniscal tear and not to complicate arthroscopy.