The concept of a reconfigurable optical leaky-wave antenna (LWA) based on microfluidics technology is presented. The host waveguide is composed of a microfluidic channel which is periodically loaded by a set of silicon corrugations. The refractive index of the fluid flowing along the host waveguide can be dynamically changed, thus allowing to control the pointing angle of the radiated beam by affecting the n = -1 Floquet harmonic of the periodic structure. This device can be rigorously regarded as a variable optical grating, but the LWA formalism allows a detailed analysis and design of the radiation characteristics. Simulations fully demonstrate the validity of the proposed implementation. © 2014 European Association on Antennas and Propagation.