Tasmania's health department is urging pregnant women to get vaccinated against whooping cough after a recent spike in the disease.

Pregnant women in Tasmania are being urged to get vaccinated for whooping cough after a spike in the bacterial disease that can be deadly for newborns.

There have been 170 whooping cough cases throughout the state since early August, and 239 this year, compared to 40 reported cases in 2017.

Cases are most prevalent in the state's north, including around Devonport, but are also increasing in the south.

"Schools are reporting student and staff illness with children aged under 14 years most affected, particularly those from five to nine years old," Director of Public Health Mark Veitch said on Monday.

Whooping cough vaccines are free for pregnant women, with the disease life-threatening to newborn babies.

The vaccine is also free for children aged six months, two years and four.

The last Tasmania-wide whooping cough outbreak was in 2012 with more than 1200 notified cases.

Initial symptoms are similar to the common cold but can increase to severe coughing causing vomiting, fainting and difficulty breathing.