Abstract: A mobile phone in-call indicator for connecting to an antenna of a mobile phone is provided. The in-call indicator mainly includes a lower base having a lower bolt part and an externally threaded head, an upper base screwed to the threaded head of the lower base and having a light-emitting diode and a circuit board mounted thereto, and an ornamental cover rotatably fitted around the upper base to cover the upper base. In case the in-call indicator is mounted onto the mobile phone with the ornamental cover facing toward a direction not exactly the same as that of the mobile phone and therefore resulting in an inconsistent appearance, the cover may be adjusted in its direction simply by separating the upper base from the lower base and turn the upper base relative to the cover.