A foreign diploma does not always need formal recognition—but some professions are regulated, and employers may still want a credential evaluation to understand your qualification.
First ask: is the profession regulated?
For a regulated profession you may need formal professional recognition or registration before you can practise. Healthcare is a common example, with professions that can require BIG registration. For non-regulated work, a diploma evaluation can still help an employer understand the Dutch-equivalent level.
Useful starting points
Use the Dutch government/Business.gov regulated-professions information and IDW for international credential evaluation. For healthcare, check BIG-register requirements separately.