Cell culture techniques are the vital basis for the large majority of experimental cancer research. During the last 50 years, a long list of standard procedures and formulas have been developed for cell cultures. Almost all malignant tumour entities were established as immortal cell lines, and many of them are available commercially. The reproducibility and reliability of these cellular systems, however, is highly influenced by cell and tissue culture conditions, and many cellular functions can be modulated purely by altering the conditions of the culture. This chapter provides an introduction into basic principles of tissue and cell culture, which are very important but not limited to cancer research.