An updated compilation of marine algae for Inhaca Island, Mozambique is provided. The list comprises 205 species and infraspecific taxa (64 Chlorophyta, 23 Phaeophyta and 118 Rhodophyta). Nineteen of the seaweeds (9% of all records) have recently been placed into synonymy. The most common orders are Cladophorales (including Siphonocladales), Caulerpales, Gigartinales and Rhodymeniales. A (R+C)/(p) ratio of 7.91 indicates strongly the presence of a tropical seaweed flora.