Parkinsons and Alzheimers disease are neurodegenerative disorders, which show in addition to the well-known symptoms also social impairments. Moreover, autism and autistic spectrum disorders are defined by such impairments as aberrant reciprocal social interactions, deficits in social communication and repetitive behavior. Due to the fact that social deficits and stereotypic behavior are specific for Parkinsons and Alzheimers disease as well as for autism, three different mouse strains were tested for social and repetitive behavior in this study. In addition to the EPM, Nest Building Behavior, Modified Irwin Test and Two Choice Swim Test, new behavioral tests such as the Marble Burying Test, Autogrooming Analysis and the Three Chamber Social Test (3CST) were established. These tests should show social deficits and repetitive behavior in the transgenic mouse strains. Therefore, Tg ?-Syn mice as a model of Parkinsons disease, Tg APPSL mice as a model of Alzheimers disease and their nTg littermates were tested in 7 different behavioral tests. The age of the different mouse strains was chosen according to the appearance of pathological hallmarks. BTBR inbred mice as a model of autism, acted as a positive control group in all tests. It can be concluded that the ?-Syn mouse strain showed social deficits in the 3CST, whereas Tg APPSL mice showed no deficits in social behavior unlike AD patients. Therefore this ?-Syn mouse strain is qualified to check social deficits. As expected, BTBR mice exhibited social deficits in the 3CST. Additionally, the results of the Autogrooming Analysis showed that ?-Syn and APPSL mice did not exhibit repetitive behavior, in contrast BTBR mice displayed repetitive behavior. In the Marble Burying Test, ?-Syn mice showed a normal burying behavior, since no significant differences between Tg and nTg ?-Syn mice were observed. Tg APPSL and BTBR mice exhibited a decreased marble burying behavior compared to nTg APPSL mice.