Among, humankind's old cultural heritages, Islamic architecture is a livingreality that continues to thrive, evoloving and renewing itself in newer con-texts. Lessons learned from the study of Islamic envrionmental design arenot only useful to the new generation of Islamic designers, but are also rele-vant to designers of other cultures. In this respect, architecture as an artform that can be esoteric and yet useful is a crcial reflector of a society'sspritual attitudes and daily customs, its me aphysical beliefs and pragmaticmorals. The language of Islamic architecture, therefore, like the architec-ture of a language, is a significant story-teller about Islam's intricately-woven system of beliefs and customs. Order and randomness in architectural productions are traits that not onlycontrast societies in their different stages of development (i.e., primitivevs. developed, pre-industrial vs. industrial), but also contrast culturesacross a differentiated specturm (i.e., Islamic vs. Christian, Asian vs. Eu-ropean). Such constrasts are furthermore mainfested within the same cul-ture as the context changes (i.e., religious vs. secular, residential vs. com-merical). In this connetion, apperances such as geometric and organicpatterns, formal and informal organizations do not remain detached, physi-cal entities, but are signifiers of a society's deeper adherence to social andspiritual ideologies.This paper, in accepting architecture as a vehicle that carries culturalmessages, uses this vehicle to explore the occurrence of order and random-ness in patterns of Islamic architecture and urbanism as a manifestation ofthe source culture's unique but hidden currents. This exploration revealsthe connetions that exist between form and content, between artifact and theknowledge the artifact carries; or to put it differently, between physicalpatterns such as geometric systems, spatial organizations and the social andspiritual messages these patterns convey. The exploration further revealsthe contrasts that exist in the patterns between informal rural layouts andformal urban layouts, between random residential environments and or-dered monumental complexes, between the vernacular and high style arcih-tecture.Drawing from a variety of examples, this paper identifies four types of or-der and randomness as they appear either in isolation or intermingle inmixed settings creating different patterns of Islamic designs in layouts ofbuildings, villages or towns. They are the unified order of sacred architec-ture, the lively randomness of vernacular architecture, the interminglingof order within randomness or randomness within order in mixed solutions;and finally the fragmented and divisive order of new subdivisions. Through astructural search we can discover the order and wholness that is hidden inthe random patterns or the fragmentation that is harbored by the orderedlayouts. The significance of these patterns and their connections to the innerstructure of the society from which they take source cah hep us not onlywith the understanding of the past, but also in the formulation of contempo-rary design applications.