We present recent results on fabrication of micrometre- and sub-micrometre-scale structures in polyethylene glycol diacrylate (PEG-DA), a biocompatible hydrogel, useful in biomedical applications. The hydrogel structures were fabricated using two laser-based techniques; laser direct-write photopolymerisation, and multiple-beam laser interference photopolymerisation using continuous wave, nanosecond pulsed and femtosecond pulsed lasers, with light wavelengths of 266 nm, 355 nm, 532 nm and 800 nm. Through these techniques, we demonstrated the ability to fabricate fine structures over large areas without the use of templates or masks. Such structures can be useful for a variety of applications including cell biological studies, tissue engineering and drug delivery.