Nineteen watercolours of Odonata which until now have remained unidentified were studied in order to establish their identity. They form part of the 1 256 watercolours of the collection of Edmond de Selys Longchamps housed in the Royal Belgian Institute for Natural Sciences (RBINS). Selys wrote on each watercolour either no, partial or full species names that were never published. We examined previously published literature, specimens in the RBINS and consulted with various experts in hopes of associating these watercolours with current species names. We were able to associate ten watercolours with current species names and four only with genera, while four watercolours remain unidentified. In one watercolour the male is identified on the species level and the female on the generic level. We have thus far been able to associate 96 % of the entire odonate watercolour collection with current species names.