This study investigated the influence of P. falciparum Parasitaemia on some selected haematological parameters in children (6-59 months), at Bulumkutu Health Centre, Maiduguri Borno State, Nigeria. Between November 2015 to February 2016. The aim was to determine the influence of parasites densities on some selected haemotological parameters, to assess the influence of sex distribution of children on the influence of parasteamia in relation to some haemotological parameters in children malaria. A total of 210 children were enrolled in this study consisting of 8 (41.90%) patients infected with P. falciparum malaria a total of 52 (.24.76%) were male tested positive and 36 (17.14%) were females tested positive. While 122 (58.10%) were negative malaria children, out of which 64 (30.48%) were male tested negative and 58 (27.62%) were female tested negative. Haemotological parameters were analyzed using sysmexhaemaology auto-analyser (2011), while the Giemsa stained was prepared from the stock solution, and the testing for p. falciparum malaria and malaria parasite density count was carried out using the Giemsa stained thick and thin blood film. The mean PCV, Platelet Counts and lymphocyte of subjects was significantly lower compared to malaria negative individual. (27.31%, 342.5 x 10-9/µ/ and 41.80%) versus (34.52%, 382.5 x 10-9/µ/ and 43.89% respectively p = 0.05). While the mean WBC, Neutrophil, Eosinophil, Lymphocyte and Monocyte of malarial infected subjects was significantly higher among malarial infected subjects compared to the malaria negative children. (11.61 x 10-9/µ/, 52.53%, 2.28%, and 4.121%) versus (10.25 x 10-9/µ/, 48.77%, 2.14%, and 4.057%) respectively (p = 0.05). The result further showed parasite density count also significantly influences the haematological parameters of male and female subjects as mean of PCV, WBC, lymphocytes and monocytes of male subject was significantly lower compared to their female counterparts. (26.85%, 11.398X10-9/ µl, 43,782% and 4.424% respectively P=0.05) Hence, the need for prompt and treatment of clinical malaria episode with anti-malaria drugs for children infected with malaria in Nigeria.