Mutiu is the founding and Principal Partner of Smithworth Partners and in that capacity coordinates the various practice areas of the Firm.
He established the firm in 2008, and he has been a litigation partner of the firm since then. He specialises in commercial litigation and has litigated an extensive range of issues, including maritime law, banking, intellectual property, contract law, receiverships and insolvency, both at trial and appellate levels.
Mutiu has represented both local and foreign clients in arbitration before arbitral institutions and as been invited as a co arbitrator over arbitral proceedings
Mutiu has also been involved in public interest litigation and law development efforts in Nigeria.
He contributed and wrote articles for the International Corporate Law Bulletin journal as a Consultant Editor. Furthermore, he currently is on the Editorial Boards of the Nigerian Monthly Law Reports and the Commercial Law Reports of Nigeria and he contributes articles to the "Annual Review" of the latter.