Despite guidelines for the diagnosis of oral lichen planus (OLP), there has been much difficulty and ambiguity in rendering a straightforward diagnosis. The root of the problem might arise in not following universal guidelines and being too rigid and unilateral in making a diagnosis. Because of its autoimmune pathogenesis, the dynamic nature of OLP has further fueled confusions. This has had repercussions in the form of controversies in its diagnosis, treatment protocols, research, and most importantly, its potentially malignant nature. Oral lichenoid dysplasia (OLD), an enigmatic entity, proposed by Krutchkoff and Eisenberg, has not found universal acceptance by the pathology community. The objective of the present review was to outline these debates and discuss ongoing controversies regarding OLD and uncertainties in the diagnostic criteria of OLP.