People living in Rainham will live five years longer than people who live just a few miles away in the centre of Chatham.
Data from the Office for National Statistics shows the average life expectancy for people in certain parts of Medway - including Cuxton and Halling and Rainham Central - is 82 years.
By contrast, in Chatham Central average life expectancy falls to 77 years.
Other wards with higher life expectancies include Hempstead and Wigmore, Lordswood and Capstone, Walderslade and Rainham North - all at 81.
Areas with lower average life expectancies include Luton and Wayfield, River, and Gillingham North and South - all at 78.
Life expectancy for women varies by 5.5 years depending on where they live, while for men it varies by 6.5 years.
Average life expectancy for women in Medway is 81.7 years - lower than the England average of 82.6.
While the average life expectancy for men in Medway, 77.6, also trails the national average of 78.6.
The ‘health gaps’ have been highlighted by the Medway Better Start for Children campaign which is bidding for Big Lottery funding to improve local services for families.
The Towns could receive between £30m and £50m which would be used to tackle issues such smoking, teen pregnancy, nutrition, breastfeeding and obesity - particularly in the more deprived parts of Medway.
The bid is being led by the charity Family Action, working with Medway Council and the NHS.
David Holmes, chief executive of Family Action, said the life expectancy figures highlight the lifelong benefits of transforming support for families during pregnancy and in their child’s first years.
He added: “Helping people to live longer, healthier lives necessitates targeted investment in services to support pregnancy and the first years of life as well as throughout the life course.
“Only when all families receive the help and support they need to give their children a good start will life expectancy levels in all areas improve.
"Achieving this could take many years but the Lottery funding will provide the ideal launching pad towards better outcomes for all.”
Medway, is one of 15 areas to have been short-listed for a share of £165m of Big Lottery funding to improve the health and wellbeing of children under four. The winning bids will be announced in June.