This paper focuses on the question whether or not the container liner shipping industry is an oligopoly. Although liner shipping literature has been occupied with this question, few authors have examined the market structure of the containerised liner shipping industry. The study of the market form at trade level fills in a gap in the literature. The empirical investigation uses concentration ratios to measure the degree of concentration. The results allow us to determine the degree and type of oligopoly. The conclusion shows that the containerised shipping industry is characterised by increased concentration. Some trade lanes may be characterised as a loose oligopoly; others as a tight oligopoly.