Retowski was born in a noble family in Danzig and was given an early education at home.
He then went to the Johannisschule at Danzig and went in 1868 to the University of Königsberg where he studied natural history.
In 1872 he moved to Russia where he worked as a private tutor and in 1877 he received Russian citizenship and joined as a director at the museum in Theodosia in Crimea.
In 1884 he went to the Abkhazia and Kuban region on behalf of the Senckenberg Society for Natural Research.
In 1900, on the recommendation of the Grand Duke Alexander Mikhailovich, he moved to head the numismatics department of the Hermitage museum in St. Petersburg where he worked until 1924.