Purpose: The Markets in Financial Instruments Directive (MiFID) II directive was enforced in the EU in January 2018. While EU-member states implemented this directive in their national legislation, investment firms are still enforcing compliance. With the purpose of “investor protection”, the purpose of this study is to investigate the effectiveness of transparency, suitability, warning and information requirements. How do investment advisers view and embrace these MiFID II requirements? Are differences evident within this group of professionals? Design/methodology/approach: In total, 267 Dutch investment advisors serving non-professional investors daily completed structured surveys on their opinion of the acceptance and effectiveness of the MiFID II requirements. The findings are compared with existing literature to examine similarities with other legislation. Findings: The results demonstrated differences depending on the investment firms’ size and investment advisors’ seniority and gender. Professionals should be critical of new legislation and regulations, as it limits their autonomy. However, female investment advisors and those with up to ten years’ experience are less critical of the effectiveness of the MiFID II requirements, embracing them without discussion. Investment advisors in large investment firms believe that MiFID II contributes to investors’ interests, whereas those in small and medium-sized investment firms often do not share this opinion. For example, respondents considered cost transparency an effective requirement to achieve better investment services and protect investors’ interests. Originality/value: The effectiveness and applicability of legislation are often viewed from a legal perspective, and enforcement is essential. However, this study explores legislation from the perspective of professionals under supervision.