Interactions of cells with biomaterials dictate their biocompatibility and biofunctionality, and are strongly influenced by surface properties. Moreover, it is important to control cell adhesion to surfaces for biological studies and diagnosis. Surface properties influence protein adsorption in terms of conformation and quantity adsorbed that further affects cell adhesion and proliferation. Several works have demonstrated that wettability influences cell attachment and proliferation. However, most studies have reported the influence of the surface energy of smooth substrates within a limited range of wettabilities. By controlling the roughness and the hydrophilicity of the surface, one can obtain biomimetic substrates with a wettability ranging from superhydrophobic to superhydrophilic. This review intends to summarize recent works, where the interaction of cells with surfaces with extreme wettabilities was investigated. Such information may be relevant in different biomedical and biological applications including diagnosis, cell biology, or tissue engineering.