Carrageenan yields of five Tanzanian species of Eucheuma have been determined. The tnean yields obtained were 72.8%,69.0%, 65.0%, 58,0% and 54.0% for E. spinosum J. Agardh, E. striatum Schmilz, E. platycladum Schmitz, E. okamurai Yamada and E. speciosum J. Agardh f mauritianum Boergesen, respectively. Infrared spectroscopy studies were also con-ducted. E. striatum and E. okamurai showed absorption peaks characteristic öl -carrageenan; E. spinosum showed peaks characteristic of t-carrageenan. E. speciosum f. mauritianum and E. platydadum showed peaks more closely resemhling those of i- than -carrageenan.