The K-9 Unit has been part of the State Police since 1963. The teams, comprised of a specially trained trooper and dog, are geographically assigned to all troops within the state. The patrol dog teams are also cross-trained for drug detection, cadaver detection, and explosives detection. All teams are trained and certified to New England State Police Administrators Compact (NESPAC) standards, as well as the United States Police Canine Association (USPCA) standards.

The K-9 Unit is responsible for training patrol and specialty dogs for the New Hampshire State Police and other local in-state and out-of-state departments. The K-9 Unit trains teams in a basic patrol school which includes obedience, officer protection, criminal apprehension, building search, evidence recovery, crowd control and tracking of wanted or missing individuals. Each team tests for recertification annually.

The K-9 Unit was involved in over 1500 missions in 2007. Explosive-detection teams assisted U.S. Secret Service with providing support to presidential campaigns. Patrol-Narcotic teams assisted several communities with school searches upon their request. Other narcotic teams were involved in the detection of illicit drugs on the highways and in homes assisting drug units, U.S. Customs, DEA and other agencies. Narcotic detection teams also assisted corrections with searches of their facilities. Patrol teams were involved in the searches for wanted and lost individuals. Several teams were vital in the apprehension of burglary suspects and other individuals who fled from law enforcement.

The K-9 Unit gives support for the annual motorcycle week in Laconia during the month of June. Assistance is also provided by the K-9 Unit at the New Hampshire International Speedway with both patrol and explosives detection teams.

With the addition of new teams who are specialized in Patrol-Cadaver, Patrol-Narcotic and Explosives Detection, the K-9 Unit will continue to respond to the needs of law enforcement and the citizens of the State of New Hampshire.