One of the logic approaches to improve the contemporary design criteria of the Minarets understands the design methods of the built Minarets of Mamluks. To demonstrate how the geometrical proportions and environmental aspects played the role of design generator which remained the backbone of the process of “designing" a geometrical analyses of various designs of Mamluk Minarets were presented by concentrating on the derivation process of the design idea. By geometric morphological analysis of 20 Minarets a not fixed certain proportional relationships were found. The study depended on analyzing the proportions of the geometric shapes and the Minarets heights in relation to the whole composition to suggest the proportions code and the environmental principles, which may be considered as the inherent design method that govern the design of the Minarets in Cairo of the Mamluks. The research reached to suggest a design generative technique; this technique is a combination of architectural grammar which can be understood as a bundle design principles which formulate a design guideline. This technique illustrates how Mamluk architects proceeded to apply the proportions code and environmental principles to the practical problem of Minarets design, the research name it ‘Unwritten Design Method', which is orderly and methodical arrangement of proportions to produces the Minarets design.