This study sets out to investigate the pre-service science teachers levels of relating scientific knowledge to their daily lives. The sample consisted of 217 pre-service science teachers enrolled at science education departments of four universities, namely, Gazi, Middle East Technical, Hacettepe and Sakarya. Research data were obtained from writing scientific reasons of 20 open-ended statement related to physics, chemistry and biology matter. Data which were determined by pre-service teachers writings were coded as true, false and blank, and they were analyzed. Findings regarding the level’s of relating daily lives to the scientific knowledge revealed that pre-service teachers were considerably able to relate their physics knowledge to their daily lives. They were also able to relate their chemistry knowledge to their daily lives partially, but the level of this relation was relatively lower than that of physics knowledge. In addition, pre-service teachers could relate their biology knowledge to their daily lives to a lesser extent.