The research, carried out for the Tertiary Colleges Network, found that their students completed a higher proportion of their qualifications at all levels apart from entry level, where FE college students had a better achievement record.
Tertiaries are former sixth-form colleges which expanded to provide vocational or adult courses.
Focusing on students aged 16 to 18, the report compared 10 tertiary colleges with the same number of FE and sixth-form colleges in similar parts of the country during the period 19989 to 20001.
The report found that tertiaries had a wider range of curriculum options than their sixth-form college counterparts. On average, they have 325 qualifications being taken by at least one 16 to 18-year-old, compared with 150 in sixth-form colleges. General FE colleges, which are much larger than tertiaties, have 338.
A varied curriculum can help persuade students not to drop out, the report says, especially those "entering post-compulsory education at lower levels".
Fiona McMillan, convenor of the Tertiary Colleges Network, said: "Tertiary colleges seem the most successful in providing opportunities for students to progress to higher levels once they enter the college.
"There's an important issue here about students not feeling that they have failed and that they can come to the same college as students who are more academically able and still do well. They can say to themselves, 'We have the potential to achieve,' and that opens up students' confidence and self-esteem."
Judith Norrington, director of curriculum and quality for the Association of Colleges, welcomed the findings but called for wider analysis of vocational courses.
She said: "Unless we know how far we have moved somebody on, we can't indicate potential. It's not the end point but where they started and how far they've gone that we need to know."