Abstract: We reported a case of infections caused by Haemophilus parasuis in piglets occurred in a pig farm of Taixing, Jiangsu Province in March of 2015. The definite diagnosis was made by a series of diagnostic methods. The infections in piglets caused by Haemophilus parasuis were controlled by using high sensitive antimicrobial agents recommended by antimicrobial susceptibility test. We detailed the process of diagnosis and treatment of this case and the differential diagnosis from infections caused by Streptococcus suis with emphasis on histopathological changes. This report may provide some references for veterinary practitioners in control of infections caused by Haemophilus parasuis.