Advances in photomedicine and optogenetics have defined the problem of efficient light delivery in vivo. Recently, hydrogels have been proposed as alternatives to glass or polymer fibers. These materials provide remarkable versatility, biocompatibility and easy fabrication protocols. Here, we investigate the usability of waveguides from poly(ethylene glycol) dimethacrylate for targeted light delivery and diffusion. Different hydrogel compositions were characterized with regard to water content, chemical stability, elasticity, refractive index and optical losses. Differences in refractive index were introduced to achieve targeted light delivery, and scattering polystyrene particles were dispersed in the hydrogel samples to diffuse the incident light. Complex constructs were produced to demonstrate the versatility of hydrogel waveguides. © 2019 Optical Society of America.