A physiological sensor system for removably securing a physiological sensor to a garment. The physiological sensor system generally includes a physiological sensor adapted to be removably connected to a garment. The sensor may be adapted to detect a physiological condition, such as oxygen level or pulse rate. The sensor may include a connector such as a magnetic ring or hook-and-loop fastener to removably connect the sensor to the garment. The garment may include a window through which a light beam from the sensor may pass to illuminate the underlying body and sense various conditions. A control unit may be provided for controlling the sensor and processing data received therefrom.