The present invention relates to an antifouling coating composition, an antifouling coating film, a substrate with an antifouling coating film and a production process for the substrate. The antifouling coating composition includes a hydrolyzable polymer (A) having a structural unit represented by the following formula (1) and having a weight-average molecular weight of 1000 to 5000 and an antifouling agent (B) including (b1) 4-bromo-2-(4-chlorophenyl)-5-(trifluoromethyl)-1H-pyrrole-3-carbonitrile, and has a volatile organic compound (VOC) content of not more than 400 g/L. [In the formula (1), M represents zinc or copper, and R1 independently represents a hydrogen atom or a methyl group.]