In recent years, many researchers have paid more and more attentions on the use of Nanotechnology. Solid lipid nanoparticles (SLNs) are emerged as a promising alternation herein to emulsions, liposomes, microparticles and polymeric nanoparticles for their advantages. As promising drug carrier systems, SLNs are valuable for nanomedicine and have been widely used as delivery systems mostly for drugs and macromolecules like proteins, oligonucleotides and DNA by various application routes, such as intravenous, oral, duodenalous, intramuscular, pulmonary, intranasal, ocular, rectal and intraperitoneal administrations. It has been shown that SLNs can increase bioavailability, alter pharmacokinetic parameters and tissue distribution of the drug loaded. In this review, we will primarily focus on the absorption, pharmacokinetics and disposition properties of SLNs for their possible applications in drug delivery.