The invention relates to a new process for the preparation of nano-structured and/or nano-porous surfaces, coatings having a nano-structured and/or nano-porous surface and articles comprising said coatings. The invention also relates to the use of coatings according to the invention, in particular as anti-reflective coatings. The process for the preparation of the surface nano-structured and/or nano-porous coatings is a process comprising the steps of: a) applying a mixture to a substrate which mixture comprises: i) reactive nano-particles; ii) at least one solvent; iii) optionally a compound having at least one polymerisable group, in an amount that results in an increase in the transmission of at least 0.5%, for at least part of the electromagnetic spectrum between 400 and 800 nm, after the mixture has been applied and cured on a transparent substrate, in comparison with the same substrate without a coating; b) inducing crosslinking and/or polymerisation in the mixture applied to the substrate.