St John Ambulance trained 250,000 employees in workplace first-aid skills last year, a 10 per cent increase on the year before.
Nic Suggit, head of training at the organisation, said the increase was proof that companies are "beginning to acknowledge the importance of first aid at work and the safety of their employees".
He added: "All employers need to provide adequate first-aid cover both as a legal requirement and as part of a duty to care for their employees."
As the UK's leading provider of first-aid training, St John Ambulance has 3,000 trainers across the country who teach more than half a million people each year.
The organisation charges companies for the sessions, with prices varying according to the location of the business and number of employees.
As well as First Aid for Work, the organisation runs courses for children and the general public.