Nicolaj Kleist mainly specialises in issues relating to the life science sector and energy and supply utilities.

He advises pharmaceutical and medical device companies on regulatory matters, including marketing authorisations, reimbursement, advertising and EU law. He also advises energy and supply utilities on capital and price issues and other public law matters. He further assists in connection with litigation before public authorities, complaints boards and courts.

Nicolaj Kleist has been a lecturer in contract law and property law at the University of Copenhagen.