We have studied the dynamical and structural properties of destabilized nanoparticle suspensions by a combination of small‐angle neutron scattering (SANS) and diffusing wave spectroscopy (DWS). SANS and DWS provide structural and dynamic information about opaque samples online during the gelation process. With our new experimental setup we access a broad range of length and time scales perfectly suited for the (non‐invasive) investigation of dense nano‐ and mesostructured complex fluids and solids. © 2004 American Institute of Physics