This chapter argues that participatory interventions (PIs) are effective means for increasing employees’ pro-environmental behaviour (PEB). We rely on the Self-Determination Theory to accentuate that the fulfilment of the three basic psychological needs – autonomy, competence, and relatedness – is necessary before expecting employees to behave with volitional PEB. To provide guidelines of how PIs can be conducted within organisations, we illustrate a prototypical workshop process (detection, decision, implementation) to ensure PEB’s integration into work routines. Furthermore, we highlight the essential elements of a PI, such as (1) change agents’ sufficient facilitation skills of establishing an autonomy-supportive atmosphere, (2) the analysis of the perceived (dis-)advantages associated with PEB, and (3) documentation of agreed measures to establish PEB fostering norms. Finally, we discuss process evaluation and a stronger focus on employees’ characteristics as avenues for further research, and derive implications of how practitioners can enhance PEB by using PIs.