Five new species of the endemic giant pill-millipede genus Zoosphaerium from Madagascar are described: Z. muscorum sp. n., Z. bambusoides sp. n., Z. tigrioculatum sp. n., Z. darthvaderi sp. n., and Z. heleios sp. n. The first three species fit into the Z. coquerelianum species-group, where Z. tigrioculatum seems to be closely related to Z. isalo Wesener, 2009 and Z. bilobum Wesener, 2009. Z. tigrioculatum is also the giant pill-millipede species currently known from the highest elevation, up 2000 m on Mt Andringitra. Z. muscorum and Z. darthvaderi were both collected in mossy forest at over 1000 m (albeit at distant localities), obviously a previously undersampled ecosystem. Z. darthvaderi and Z. heleios both possess very unusual characters, not permitting their placement in any existing species-group, putting them in an isolated position. The females of Z. xerophilum Wesener, 2009 and Z. pseudoplatylabum Wesener, 2009 are described for the first time, both from samples collected close to their type localities. The vulva and washboard of Z. pseudoplatylabum fit very well into the Z. platylabum species-group. Additional locality and specimen information is given for nine species of Zoosphaerium: Z. neptunus (Butler, 1872); Z. villosum Wesener & Sierwald, 2005; Z. amabile Wesener, 2009; Z. tampolo Wesener, 2009; Z. smaragdinum Wesener, 2009; Z. viridissimum, Wesener, 2009; Z. pseudopiligerum Wesener, 2009; and Z. analavelona Wesener, 2009.