The objective of study is to identify the factors influencing the circulation of the African Swine Fever virus (ASFV) in apparently healthy pig farms. The study was realized in the provinces of Chari Baguirmi, Mayo Kebbi East and N’Djamena. Started with is census of 492 farmers who had already registered ASFV. Among them 198 consented to participate in this study. Total of 346 sera were collected and analyzed by the competition ELISA for the detection of antibodies directed against the ASFV. Intrinsic factors influencing ASFV circulation on farms had variable seroprevalences. They were 18.51 % in whole boars and 16.21 % in castrated boars. In sows 6.66 % in pregnant sows and 14.59 % in non-pregnant sows (P = 0.0061). Extrinsic factors were linked to the floor of the pigsty with seroprevalence of 19.56 % in baked bricks and 18.36 % in earth (P = 0.00405). Seroprevalence of 4.72 % among stray pigs (P = 0.0008459) and 18.05 % among farmers who introduced a new pig into their herds (P = 0.007634). Seroprevalence of 20.27 % was linked to the presence of mole ticks in buildings (P = 0.00000036). This work showed that ASFV circulates in pig farms in Chad, without any visible clinical signs. Factors influencing circulation of the ASFV in pig farms are linked to the physiological and general state of the pigs, breeding system, floor of the pigsty, means of transport of boars and sows for reproduction, to presence of ticks in buildings and farmers' poor knowledge of biosecurity. Presence of this virus in pig farms is maintained by the failure to control the chain of contamination of the disease and poor breeding practices. ASF is far from being eradicated in Chad. Administrative and health authorities must intensify awareness campaigns among farmers to control the virus.