Lambros Eftaxias donated dresses of the Vouros-Eftaxias family, as well as a plot with a building for the expansion of the Benaki Museum (main building in Koumbari Street). He assigned an estate in Agion Asomaton Street, where the Museum of Islamic Art is housed nowadays with retaliatory terms towards the Museum of the City of Athens. He also donated a large number of ancient Greek objects of the Classical Period to the Museum of Cycladic Art and several sums of money to organisations and societies related to sports and culture.