Little archaeobotanical data has been so far recorded from historical periods in the Oman peninsula. The excavations carried out under the direction of M. Mouton (CNRS) in 2010 and 2011 of a burnt building at Mleiha (Sharjah Emirate) dated to the end of the pre-Islamic period (middle of the 3rd century AD) have now provided a large amount of exceptionally well-preserved organic remains such as seeds, fruits, charcoals, fibres and amorphous remains. This discovery gives us the unique opportunity to reconstruct the agrarian economy and bring to light new information about the diffusion of plants during this period. The results of both seed and charcoal analysis show the presence of an oasis agrosystem nearby the site, mainly based on the cultivation of date palms, irrigated thanks to wells giving access to the groundwater. The seed and fruit assemblages reflect the typical vertical organisation of date palm garden containing also cereals, pulses, vegetables and fruit trees. In addition to these common plant products regularly found within contemporary Middle Eastern oasis agrosystem, several new species highlight the important connections between Mleiha and the Indian sub-continent. For most of these, they constitute the earliest evidence of their presence in the Arabian Peninsula and likely represent imported products. Nevertheless, we will question if some species may also have been cultivated locally by examining the ecological features, the agronomic requirements and others archaeobotanical evidence for the Arabian Peninsula as well as from surrounding regions.