Primary care is characterised by a broad understanding of health and illness. Due to the high degree of diagnostic uncertainty in primary care, medical tests play a lesser role in this domain than in specialist medicine. However, medical testing is also becoming increasingly important in primary care, raising questions about how these technologies are integrated into everyday practice. Drawing on qualitative interviews with Austrian doctors, this article shows that the use of medical tests in primary care is often interwoven with practices of care. Doctors engage in care around the use of medical tests by assessing the impact of diagnostic knowledge and addressing patients' needs before and after testing. They also demonstrate care through the use of medical tests, such as administering them to comfort patients rather than for strictly clinical reasons. Situating these findings within the sociology of diagnosis, I argue that diagnostic processes not only guide medical care provision but are also closely intertwined with practices of care.