His numerous obituaries attest to his distinguished career and the loss felt in his field of study at his sudden and early death from pneumonia.
Upon his return to France, Riefstahl immersed himself in the study of Oriental art but, following the outbreak of WW1, he was forced to move and took up residence in the United States.
The sales Liquidation des biens Meyer-Riefstahl, ayant fait l'objet d'une sequestre de guerre took place in 1923 and 1925 at Hôtel Drouot, Paris.
In the same year he married his wife Elizabeth Titzel (1889–1986), an expert in ancient Egyptian art, and together they embarked on a number of research expeditions to the Near and Middle East.
Riefsthal acted as an advisor to a number of organisations, such as to the Pennsylvania Museum, Philadelphia, on the consultative committee of Ars Islamica and as a member of the council of the American Institute of Persian Art and Archaeology, amongst others.