Anaplasma bovis is an intra-cytoplasmic gram negative rickettsia that infects monocytes and causes bovine monocytic anaplasmosis, which can be in peracute, acute, sub-acute or chronic form. A total of 170 tick DNA pools from 11 different tick species from Ngorongoro Crater were amplified for Anaplasma species using PCR targeting a gene fragment of 452bp of the 16S rRNA gene. Ten percent of 170 pools tested positive for Anaplasma species from seven tick species. On sequence analysis, Anaplasma bovis was detected in Amblyomma gemma, A. variegatum, Rhipicephalus appendiculatus, Rh. evertsi, Rh. praetextatus and Rh. pulchellus. The sequenced pools which revealed presence of A. bovis were from questing ticks and in moribund grass cover except Rh. evertsi which were from buffalo and zebra. This suggests that probably buffalo is an important reservoir of Anaplasma bovis and are the favourite hosts for Rh. evertsi. Detection of Anaplasma bovis suggests that probably the rickettsia contributed significantly in compromising the immunity of nutritionally stressed susceptible animals in the crater in 2000-2001. Therefore, susceptible livestock and wildlife in the crater are at risk of contracting the infections when nutritionally stressed.