A checklist of millipedes (Diplopoda) known to occur in Tanzania is given. Based on all available literature and abundant hitherto unpublished material, 296 species of millipedes are recorded, including seven species never before recorded from the country, viz., Helicochetus digititarsus Kraus, 1957, Helicochetus gregorii (Pocock, 1896), Geotypodon intermedius (Carl, 1909), Plethocrossus nairobinus Attems, 1914, Lophostreptus bicolor Carl, 1909, Oreiadessa diana Hoffman, 1990, and Chondromorpha xanthotricha (Attems, 1898). Eight species erroneously recorded from Tanzania are excluded from the list. A few records from Kenya and Uganda are also given, including the first record of Otostreptus gilvitarsus (Attems, 1914) from Kenya. A historical account of millipede collecting in Tanzania is included.