If you are from the EU/EEA, Switzerland or Croatia you are free to work and there are no restrictions.
If you are from a country outside the EU/EEA, or you are not from Switzerland or Croatia, there are some restrictions if you wish to work alongside your studies. You will require a work permit and you will only be able to work for a maximum of 16 hours a week; as an alternative, you may also work full-time but only during the summer months of June, July and August. In this case, your employer will need to apply for the work permit on your behalf.
For more information about studying and working in the Netherlands, see the Study in Holland website.