Further education colleges need to give their staff more job security, better prospects and improved training.
The inspection agency Estyn wants to see standards of professional development match those in schools, where teachers have a clearer career structure.
Nearly a third of schools inspected in 2004-5 received the top grade for teacher-training and support compared with 9 per cent of lifelong learning providers, a category that includes FE colleges, work-based learning and adult education.
But fforwm, the association which represents Wales's 25 FE colleges, argues comparison with schools is difficult because of different funding arrangements.
In its report into staff development in lifelong learning, Estyn found there is insufficient training for middle managers and too little evaluation of staff development in FE. Teachers paid hourly - a fifth of FE teachers - miss out on training, and there are not enough opportunities to support the use of Welsh language.
A spokesperson for fforwm, which concludes its two-day annual conference in Llandudno today, said: "We need to make sure that where comparisons with schools are made, Estyn is comparing like with like.
"Unlike schools, colleges cannot give new staff a reduced teaching commitment in their first year because the funding isn't there."
Schools also benefit from extra money for teachers' second and third years in the profession, as well as continuing professional development, funded by local education authorities and the General Teaching Council for Wales (GTCW).
The Assembly government has floated the idea of a professional body for the 7,000 FE teachers in Wales to "to set and safeguard" professional standards, and informal talks have taken place between the GTCW and fforwm.
fforwm's spokesperson said: "We are looking to develop a professional teaching body for FE staff. One of the benefits of the GTC for school teachers is that it encourages individuals to take part in staff development."
Estyn conceded that staff development is given a high priority by nearly all FE colleges, but says a lack of planning by them to develop staff skills has caused tension in most institutions.
Overall, the report found that staffing in lifelong learning is characterised by high levels of work paid hourly, poor job security, little opportunity for career progression and an under-regulated system of teaching qualifications. Work-based learning providers struggle to attract staff because of poor pay and prospects, while 75 per cent of adult education teachers are part-time.
Coleg Gwent's principal Howard Burton said the college had significantly increased its budget for staff development this year.
He added: "The all-Wales pay deal in February (which brought FE teachers pay parity with school colleagues) has allowed the introduction of performance management for all staff.
"The conversion of more than 100 part-time teaching staff into fractional full-time appointments also means that a significant number of people not previously included in training activities can now participate."