Wood tar, extracted by dry distillation, has been used in human and veterinary medicine since ancient times. This is particularly the case of tars from conifers in the Mediterranean region, where they are still produced and used for these purposes. The ONGUENT project is focused on the multi-disciplinary investigation of the production and use of medicinal tar in a systemic way, from the plant raw material to the end product and its use, on both sides of the Mediterranean today and in the past, by characterizing their chemical composition and by assessing their actual medicinal effects, or toxicity. This poster deals with different space-times: medieval and post-medieval Provence (France) and current Atlas mountains (Morocco). From an ethnoarchaeological perspective, the aim of this research is to provide a better understanding of past technical processes and knowledges, throught the observation and analysis of current productions. It highlights the diversity of plant species from Pinaceae, Cupressaceae, and Taxodiaceae families exploited and the wide range of techniques using fire to extract tar from the wooden material (direct or indired-fired kilns, pots etc.). The recording of depositional and post-depositional processes helps in return to better interpret archaeological data.