Conwy's special educational needs service has been acclaimed by the inspection agency Estyn, despite grappling with a highly transient school population.
The arrival of pupils from outside the county has had a significant impact on the region's SEN services, said Estyn.
It found that a third of all pupils at primary-age pupil-referral units, and at the county's special school, Ysgol y Gogarth, had moved to the county in the past three years.
Some 17 per cent of the Year 6 cohort in 2000 had left the area by 2003, while 19 per cent of the Y9 pupils in 2003 were not among the Y6 cohort in 2000.
But despite this extra pressure, the SEN service was rated "excellent" by Estyn's inspectors. However, the service was pulled up for failing to reduce permanent exclusions - which stand at the Welsh average of 12 to 15 a year - and to provide full-time provision for all excluded pupils.
Conwy's director of lifelong learning, Elwyn Williams, said these issues were down to the influx of pupils from outside the authority whose families move to the large amounts of rental accommodation along the coast from Rhyl to Colwyn Bay.
Estyn believes Conwy has promising prospects for improvement and the authority was ranked outstanding for the small proportion of children - 1.8 per cent - who leave school at 16 without qualifications.
There was also praise for a team of teaching assistants which provides support for pupils in mainstream school and "the clear vision, sense of purpose and direction for the service", which has the inclusion of pupils with special needs as "a central part of the strategy".
Senior officers provide effective leadership and schools regard the SEN service highly. The number of statements maintained by the authority remains high, at 4.3 per cent, but the inspectors recognised that the high numbers of pupils moving to Conwy was a factor.
Mr Williams said: "We work hard to increase the provision. The main problem we have is the numbers of youngsters who come into this authority from outside. In the last academic year we had 48 pupils coming into Conwy with statements of special needs."
He added: "We've made progress, but if you've got more and more coming in, the gains you make with one hand you lose with the other. I think we're doing very well to be in line with the Welsh average."