The manufacturer said it had launched a consultation into the future of the plant near Grantham.
McCain is proposing to end production of a brand of microwave chips called Fries To Go, which it says is the only product made at the plant.
Jillian Moffatt, regional president of the firm, said it had been a "difficult decision" and pledged to "ensure a respectful, thorough and considered consultation period".
"McCain has operated in Grantham for over 40 years and we are grateful for the significant contribution and commitment of the site team throughout that time," Ms Moffatt added.
“If the proposal goes ahead, we are committed to working with all those affected at the site to ensure their next step is supported.”
In a statement, McCain said it had carried out a "product portfolio review", designed to ensure the firm was "sustainable, efficient and customer focused".
The Fries To Go product was "outside" its "core range" and it had been "unable to find a viable option to secure the future of the plant".
The company promised to "work with employee representatives" to explore "opportunities for transfers to other sites".
McCain was founded in Canada in 1957. The British division is based in Scarborough, North Yorkshire.
