Purpose: The primary purpose of this article is to identify the manifestations and causes of unethical pro-organisational behaviour related to the lowering of quality, as well as to propose measures that could prevent such behaviour. Design/methodology/approach: The main research method used was a literature review. The applied procedure was in line with the general methodology for conducting research in management sciences (Easterby-Smith et al., 2015). Exemplification was used as an ancillary research tool. Findings: Manifestations of unethical pro-organisational behaviour aimed at the lowering of quality include falsifying system documentation, hiding quality errors that occur in individual processes, deliberately impairing product quality by reducing the quantity of particular components or replacing them with lower-quality substitutes, providing customers with a completely different product under the organisation’s own name and reducing quality objectives. Paradoxically, the occurrence of such behaviour is fostered by excessive identification, affective commitment, organisational support resulting in a sense of indebtedness to the organisation, pressure for results and even satisfaction with one’s job. The possible measures that could prevent unethical pro-organisational behaviour include the following: applying the principle of positive discipline, entering into transparent psychological contracts, abandoning annual employee appraisals, employee rankings and bonus systems whose results depend on employee cooperation, as well as the variable part of managers’ remuneration. Research limitations/implications: A literature review is not a perfect way to obtain information. The article does not discuss all causes and manifestations of unethical pro organisational behaviour that may occur in organisations oriented towards quality. Practical implications: Based on the conclusions formulated on the basis of the conducted research, managers can significantly reduce the development of unethical behaviour (mainly by following the recommendations of E. Deming). Originality/value: While there is a large body of literature on the causes of unethical pro organisational behaviour, very little is known about their causes and manifestations in organisations focused on quality.