The chapter starts with a brief introduction into the notions of truthlikeness and approximate truth and the classification of different kinds of truthlikeness (sec. 2–3). After introducing Popper’s original definition of truthlikeness and its major shortcomings, two major families of approaches to truthlikeness are introduced that attempt to repair Popper’s definition in different ways: conjunction-of-parts accounts and disjunction-of-possibilities accounts (sec. 5). Section 6 contains a discussion of the problem of language-dependence. Section 7 introduces two different ways of estimating the truthlikeness of theories based on empirical evidence: evidential truthlikeness and expected truthlikeness. Last but not least, section 8 investigates the relation between the truthlikeness of theories and scientific realism and discusses pros and cons of the inference from empirical success to truthlikeness.