We describe a clearing method for enhanced visualization of cell morphology and connections in neuronal and non-neuronal tissue. Using Clear(T) or Clear(T2), which are composed of formamide or formamide/polyethylene glycol, respectively, embryos, whole mounts and thick brain sections can be rapidly cleared with minimal volume changes. Unlike other available clearing techniques, these methods do not use detergents or solvents, and thus preserve lipophilic dyes, fluorescent tracers and immunohistochemical labeling, as well as fluorescent-protein labeling.