3D maps in mobile devices for navigation aid have been created to overcome the weaknesses of conventional 2D maps which require users to interpret its various symbols and legends. Now it has become possible to render large and detailed 3D map of cities in mobile devices at interactive rates. Mobile devices with low computing resources may also use manipulated photos in order to give the illusion of 3D presentation. Owing to this recent development, the concept of 3D representation in mobile devices for multi-users interactive navigation aid becomes important. This will help people to navigate in unfamiliar locations. In today¿s world, mobility and communication have become essential. People may frequently find themselves asking: ¿Where am I right now?¿, ¿How do I get from X to Y?¿, and ¿How can I tell Z?¿ The proposed system of 3D maps in mobile devices for navigation aid allows several mobile device users to view their own and the other users¿ locations at the same time, while being stationary or on-the-move. This book provide the issues and challenges of 3D maps in mobile devices for navigation aid.