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This case (joined Art. 234 references) revolved around separate claims for equal treatment based on reimbursement of expenses and is notable because while it involves a case between individuals and the state, Marleasing SA v La Comercial Internacional de Alimentacion SA (1989) extended the decision to cover some cases between private individuals. Von Colson and Kamann had applied for posts as social workers with a state body, the prison service. Both were denied appointment, even though they had been placed at the top of the list of applicants by the social work committee, because of the problems and risks associated with working with male inmates. They claimed for award of contract or damages under Art. 6 of Directive 76/207 (on the equal treatment for men and women as regards access to employment, vocational training, promotion and working conditions). The German courts then made an Art. 234 reference. The ECJ held that the failure of German law to provide appropriate levels of compensation in this instance amounted to incomplete implementation of the Directive in question. However, the Directive (specifically, Art. 6) did not satisfy the Van Gend en Loos criterion for recognizing direct effect. Nevertheless, it is the duty of every member state to achieve results envisaged by applicable Directives, and the duty of every member state (under Art. 10 of the EC Treaty) to ensure satisfaction of that obligation binds all authorities within the state, including its courts. Domestic courts must interpret and apply legislation adopted to implement a Directive in light of its wording and purpose of so as to achieve the objective of the Directive.

Note the novel approach employed by the ECJ in deciding this case. Rather than treating the question before the court as one concerned with the supremacy of EC law over domestic law, the court developed a rule of construction derived from Art. 249 (ex 189) (Directives as binding on the member state to whom it is addressed, with choice of form and method left to that member state) and Art. 10 (ex 5) (requiring member states to take all appropriate measures to ensure fulfillment of the obligations arising from the EC Treaty or secondary legislation). In this way, the court determined that 'relevant portions' of Directive 76/207 (on Equal Treatment) could be relied on regardless of whether they satisfied the acte clair portions of the Van Gend en Loos criteria. In essence, the ECJ simply ignored the difficulty created by the absence of horizontal direct effect in the case of Directives and opted for an indirect approach of achieving the same result (hence the term 'indirect effect'). Nevertheless, the court's decision did leave ambiguous the question as to which domestic laws the concept of indirect effect could actually apply (on which more below).

In Marleasing SA v La Comercial Internacional de Alimentacion SA, the ECJ extended this concept of indirect effect that was developed in Von Colson to cover (at least) some cases between private parties (in addition to cases between a private party and the state).

See also direct effect, Marleasing SA v La Comercial Internacional de Alimentacion SA (1989).