The study deals with retroactivity in administrative decisions in U.A.E. It encompasses three parameters; first retroactivity in law, second retroactivity in administrative decisions, the third parameter concerns retroactivity according to legislature applied in U.A.E. The first parameter acts as an introduction to the next two which comprises the main issues in this study. The first parameter briefly discusses the principles of non-retroactivity of laws and whether legislature may overlook this principle. The second parameter categorizes administrative decisions. Into individual and organizational, the latter being subdivided into revealing and institutional laws. The effect of this subdivision on non-retroactivity is then discussed, followed by the extent to which the possibility of retroactivity as applied to legislature concerning punitive actions against employees. The third and final parameter falls into three parts. The first deals with retroactivity according to the effective legislature in U AE and its place in UAE temporary constitution and the laws of the state. The second part deals with retroactivity in administrative decisions, both organizational and individual, with example of retroactivity applied in UAE University. Part three deals with the principle of non­retroactivity in individual administrative decisions. It has been mentioned that administrative decisions may allow for retroactivity if necessary, especially in the case of retracting appointment in positions to dates previous to making these decisions, so long as there is good reason to do that. This study was conducted after careful review of contemporary legislature and the decrees of the Supreme Court of the Union UAE and the Supreme Court of Administrative affairs in Egypt, in addition to the legal opinion made by the researcher in his capacity as Legal Adviser to UAE University.