We realize signal transmission with a miniature light source fabricated by a $4\; {\rm mm}^2 $4mm2 red-emissive CdSe/ZnS quantum-dot light-emitting diode (QLED) in visible light communication (VLC). The light emitted from the 60°-designed QLED transmits in free space with a data rate of 4 Mb/s at a 3 m transmission distance by using a simple modulation scheme of non-return-to-zero on-off keying. The maximum data rate of 2.5 Mb/s with a bit error rate below the forward-error-correction (FEC) limit is achieved with the optical angles of ${\rm \pm 20}^\circ $±20∘. The influences caused by the voltage, distance, and optical angle of emitting light are taken into consideration during communication. The performance of the QLED-based light source compares favorably with other solution-processed devices in efficiency, luminance, bandwidth, transmission speed, and distance. Additionally, to the best of our knowledge, this is the first report of an investigation on the application of QLED in VLC. Our results should be instructive for further investigation on QLED communication.