Vietnamese pottery appears to have been exported by the Indian Ocean Monsoon trade since medieval times. However, the number of identified Vietnamese stoneware/porcelain remains very small by comparison with Chinese productions (< 0.1%) and the question of mis-assignment remains open. In order to evaluate the potential of on-site identification, an assemblage of 13 ceramic shards recently excavated from the medieval port site of Qalhāt (Omani coast) assigned to Vietnamese and/or southern Chinese productions by using stylistic/visual criteria has been qualitatively analysed with a portable X-ray fluorescence instrument and a transportable Raman spectrometer and compared with data recorded on a large variety of reference shards excavated from different kiln places of the Hong River bank, Central Viet Nam, and from the Cù Lao Chàm shipwreck. In the glaze/body, the zirconium, rubidium and titanium contents allow distinguishing between Vietnamese and Chinese ancient/modern productions. The potassium vs. calcium glaze content is also very efficient for the differentiation between the Chinese and Vietnamese origins. Measurements confirm ∼80% of the assignments based on eyes examination. The manganese, Rare Earth and cobalt content also contribute to identify the production places. Comparison of the glaze sections and chemometrics are used for a final comparison of the production technology: slip, overglaze or underglaze décor, etc.