Fifteen years after the enactment of the EU Directive 2008/104/EC on temporary agency work (TAWD) there are still considerable differences in the use of temporary agency work and in the legal situation, status, and working conditions of temporary agency workers within the European Union, even though these differences were one of the reasons for enacting the TAWD. This article evaluates whether the TAWD is still fit for its purpose – mainly, whether the objective of ensuring the protection of workers and the improvement of their working conditions have been achieved – by analysing its personal and material scope, taking into account the presence of other multiparty work arrangements. The article argues that an integral approach to multiparty work arrangements is needed to ensure the personal scope of the Directive is broad enough. Currently, the TAWD leaves (too) much room for deviation from the equal treatment principle, thereby missing a transparent level of worker protection. This makes the enforcement of the equal treatment principle significantly complicated. Lastly, the article argues that introducing a maximum period of the time that one temporary agency worker can be placed at the same user undertaking is the best way – the way with most legal certainty for all parties involved – to ensure that temporary agency work at the same user undertaking does not become a permanent situation for a temporary agency worker.