Introduction: Due to a lack of techniques there is only some data of testing mechanical influence on chondroctyes grown in 3-D tissue-culture over several months. In a new perfusion-chamber these mechanical factors could be studied in in-vitro tissue culture. Experimental Method: Chondrocytes which had been isolated by enzymatic digestion of mature pigs were seeted in Aga-rose on resorpable PDA/PGA (Ethisorb®) implants. These implants were cultured for 2, 6 and 12 weeks with alternating pressures of 0.5 MPa. Beneath a unpressurized control group, pressure was applied for 1 sec with a rest of 1 sec, for 2 sec with a rest of 8 sec and for 20 sec with a rest of 80 sec. Dulbecos medium was used for perfusion. Results and discussion: After 6 weeks the resorbable carrier has dissolved, in the following weeks the different groups showed different cartilage development (Fig. 1). After 12 weeks the 20/80 sec group showed collagen II and also major collagen I production in immunohistology, the 1/1 sec group showed only small traces of collagen I and masses of collagen II production. Further immunochemistry and scaning electron microscopy was able to show typical aspects of differentiated cartilage. Conclusion: The in-vitro differentiation of chondrocytes to mature cartilage is linked to certain mechanical factors. A frequency of 1/1 sec pressure is more favourable than lesser frequencies.