The association will tell ministers and local authorities that action is needed quickly.
Highland this week underlined the difficulties by launching a recruitment drive to boost its supply list for primary and secondary, joining other councils in the scramble for teachers.
Barbara Clark, the SSTA's assistant general secretary, said: "We have been warning the employers and the Scottish Office for years that they were facing a developing recruitment problem. But poor conditions, low teacher morale, poor salary scales and the attitude of employers to teachers have not helped.
"Employers have failed to provide security of employment for newly qualified teachers. We have warned them the profession will be increasingly unattractive to the bright, well qualified and enthusiastic young graduates. It will be a disaster for Scottish schools if teaching is a fall-back profession."
Bruce Robertson, Highland's director of education, said: "We would like to hear from recently qualified teachers and also those who may wish to return to work after a prolonged period of absence. We will provide training to bring staff up to date with the latest educational initiatives at local and national level."
He added: "A strong and healthy bank of supply teachers will enable us to provide the highest quality of education in our network of schools."