Background/Objective: Orphan drugs are medicinal products which treat life-threatening or chronically debilitating diseases which aff ect small patient populations. So far there is a substantial knowledge gap on actual expenditure on orphan drugs in Serbia. Therefore, the aim of this study was to provide insight into the expenditure trends of orphan drugs in Serbia. Material and methods: Annual reports on turnover and the consumption of pharmaceuticals in Serbia published by Medicines and Medical Devices Agency of Serbia (ALIMS) for the period 2006-2013 were used to extract data on expenditure on orphan drugs. Drugs were eligible for inclusion in the analysis if they had active European orphan designation and European marketing authorization during the period covered by the study (2006)(2007)(2008)(2009)(2010)(2011)(2012)(2013). Data were analysed across time series. Simple descriptive analysis and observation of chronological trends were applied. Results: Data for annual expenditure on 12 diff erent orphan drugs were available in the analysed reports. Orphan drug expenditure and share of orphan drug expenditure in total drug expenditure increased constantly from 2006 to 2010. Both began to slightly decrease over the next two years (2011)(2012), and then suddenly declined nearly threefold in 2013. Share of orphan drug expenditure didn't exceed 1% of total drug expenditure over a period of eight years. The highest share of expenditure on orphan drugs was attributed to imatinib (87.36%-97.13%), so abrupt decline in 2013 could be explained by its withdrawal from European Community Register of Orphan Medicinal Products in 2012. Conclusions: Expenditure on orphan drugs in Serbia from 2006 to 2013 was considerably low compared to total expenditure on drugs. In the last available year we noted substantial decline of orphan drug expenditure, mainly because of imatinib losing its orphan designation. A broader time horizon would be needed to investigate long term trends.