Arnold & Siedsma

Arnold & Siedsma is a well-regarded patent and trade mark attorney firm in the Benelux. The firm has a strong team of European patent attorneys, with expertise in fields such as chemistry, biotechnology, electronics, and engineering.  

Notable practitioners: Michiel Rijsdijk, Remco van Leeuwen, and Marlies Wiegerinck.

Arnold & Siedsma merged with Rouse Group in September 2025. Follow MIP's coverage of this firm here.

2025

"Arnold & Siedsma always provides thorough and to-the-point advice."

"Excellent service and knowledge level."

"Fast, good and knowledgeable responses."

"Friendly, collaborative, responsive."

"Quick, knowledgeable, good team quality wise and very agreeable."

"They always provide you the best pragmatic solutions without lecturing you about the case. That works perfectly."

"They are knowledgeable."

"They provide commercially relevant advice which is client centric."

The firm represented a healthcare client in a patent litigation before the Unified Patent Court. It also acted for Van Doorn Container Parts B.V in its patent dispute.

Case studies show trade mark disputes and protection work. For example, the firm represented Karl Lagerfeld Group in enforcement and anti-counterfeiting matters.