A formal publication outlet for the International Palaeontological Association (IPA) and the International Commission on Stratigraphy (ICS), Lethaia publishes articles of international interest in the fields of palaeontology and stratigraphy. The articles concentrate on the development of new ideas and methods and descriptions of new features of wide significance rather than routine descriptions.

Palaeobiology and ecostratigraphy are the core topics of the journal. In addition to articles, Lethaia contains shorter contributions in the form of discussions, presentations of current scientific activities, reviews and editorials.

Lethaia was launched in 1968 as a joint venture between scientists in Denmark, Norway, and Sweden, with the aim of promoting the development of modern methods in scientific publishing and of providing a medium for rapid publication of well-prepared manuscripts of wide international interest.