A themed modular ceiling and wall décor kit and system to change the theme and décor of any room with the use of rudimentary tools such as a tape measure, level and screw driver. An inexpensive and semi-permanent alternative to the permanent and expensive crown moldings requiring the services of a professional carpenter for their installation as well as removal. The modular ceiling and wall decor kit has limitless possibilities for modification in appearance and design as for instance, a room décor that is for a young child can be changed to suit an older child, or a room décor for a female changed to a male's room décor or when a themed presentation is called for in a child's room or other dedicated room such as a room displaying a sportsman's memorabilia, through the use of different designer panels in the crown molding housing of the décor kit.