An aggressive campaign to recruit graduate students from India to study at Western Kentucky University has ended badly, with more than one-third of the students asked to leave the program after their first semester, a university official said.

The university used international recruiters to find the students, compensating the services based on how many students they enrolled. The outcome, which will force the students to return to India or find placement in another university or program in the United States, illustrates a pitfall of using such recruiters.

James Gary, the chairman of Western Kentucky’s computer science program, said on Monday that “almost 40” of the students did not meet the requirements of their admissions, even though they were offered remedial help by the university.

While some students will be allowed to remain, Mr. Gary said, at least 25 of the nearly 60 students in the program must leave.