The cellular telephone case is configured for use with a personal data device. The cellular telephone case is a rigid structure. The cellular telephone case forms a protective structure that contains the personal data device. The cellular telephone case comprises a protective case and a lanyard mechanism. The protective case forms the protective structure of the cellular telephone case. The personal data device inserts into the protective case. The lanyard mechanism is a retractable cord contained within the protective case. The lanyard mechanism allows the protective case to be attached to an object.