The present invention includes well treatment fluids and methods utilizing nano-particles. An embodiment of a method of the present invention may comprise introducing a treatment fluid comprising nano-clay into a subterranean formation. The treatment fluid may be selected from the group consisting of a cement composition, a drilling fluid, a spacer fluid, and a lost circulation control composition. Another embodiment of the present invention may comprise a method of cementing. The method of cementing may comprise introducing a cement composition comprising a hydraulic cement, nano-clay, and water into a subterranean formation. The method further may comprise allowing the cement composition to set in the subterranean formation. Yet another embodiment of the present invention may comprise a treatment fluid, the treatment fluid comprising nano-clay. The treatment fluid may be selected from the group consisting of a cement composition, a drilling fluid, a spacer fluid, and a lost circulation control composition.