The five-year contract, with an option to extend for a further five years, is worth approximately £500,000 and will cover the district's open spaces, cemeteries, play areas, sports pitches and Green Flag parks.
Core works include maintenance of grassed areas, herbaceous borders, hedges, bowling greens and equipped play areas. Additional services will include tree works, woodland and copse management and specific operations for special events such as the Chatteris Festival and the Wisbech Yule Fayre.
The current contract is held by The Landscape Group (TLG), which employs local Fenland residents. All full-time members of staff will be retained by ISS, and will be transferred under TUPE legislation, an ISS spokesperson said.
"This equates to 11 employees including a contract manager, grounds maintenance operatives, grave diggers and an arboriculture team."
The new partnership will see ISS working closely with the council and community groups such as Street Pride to improve residents' quality of life, maintain open spaces and build on Green Flag successes at St. Peter's Church Gardens and Wisbech Park.
Cllr Peter Murphy, Fenland's cabinet member responsible for the environment, said: "We are looking forward to working closely with ISS to ensure that all our open spaces continue to be looked after in the best possible way.
"We take a lot of pride in the high quality of all our grounds maintenance, which has been a key factor in our terrific record in Anglia In Bloom, and we're confident that will continue. Retaining the staff from our previous contractors will ensure a seamless changeover and enable us to get the maximum benefit from the further operational improvements that ISS will be making."
ISS Facility Services Landscaping managing director Phil Jones said: "In the current challenging climate, we have worked hard to come up with an operational solution that will deliver a quality service, which all stakeholders can be proud of."
The company would focus on continuing improvement and providing efficiencies and value for money for the district, he added.
In a statement announcing it had won the contract, ISS said that its software - which captures and records data in real time - would be key to its success.
"The data field solution allows for the most effective use of the workforce by creating an inventory of all sites and associated assets and calculating the most logical, efficient and environmentally appropriate routes for the grounds maintenance teams.
"Live links to work programmes and audit reports will also be facilitated promoting full transparency of contract delivery to Fenland District Council and its officers," the statement said.