The ocurrence of canine heartworm disease Dirofilaria immitis in dogs Sinop and Guarantã do Norte, Mato Grosso State, Brazil was investigated. A total of 57 blood samples collected from dogs from coastal communities of Teles Pires River in the period between March and May 2014 were examined. The techinic udes in the circulating microfilariae research was Knott modified and Ohish staining method. No infected animal was verified in this present survey. This result shows that new surveys should be done to confirm the results or method as a baseline for new surveys.