Cadwalader has scrapped the scheme, which included a week in the New York office, because participants were not applying for training contracts.
Alison Smith, Cadwalader's head of administration, said: “The old scheme did not represent the most cost-effective means of targeting the numbers and quality of candidates we hope to obtain.”
A source at the firm believes the scheme, which cost more than £16,000, was abused by students wanting a free holiday.
The firm paid for flights to New York, provided accommodation with US lawyers and paid a weekly salary of £225.
From next summer, 10-15 students will shadow a London trainee for a day.