Objective <p>Platelets are blood cells which are critical for effective haemostasis and thrombosis. Beyond these classic functions of platelets, a range of roles for them in infectious diseases have also emerged. However little is currently understood about platelet-virus interactions. This study was performed to assess if human platelets are permissive to, and support replication of Semliki Forest virus (SFV), a commonly used model alphavirus.</p> Results <p>Uptake of the virus by washed human platelets was demonstrated with fluorescent flow cytometry using eGFP fused SFV. To explore if uptake of virus leads to transcriptional replication, RT-qPCR for SFV nsP4 was performed on platelets infected with SFV. This showed a significant increase in nsP4 RNA which increased further over time. This is the first demonstration of SFV RNA increasing within platelets and suggests that platelets may be able to support viral replication, however further work is required to clarify if this leads to production of functional virions.</p>