I am going through school to become a surgical tech.and wonder about past crimminal backgroun,about 10 yrs,ago, will affect my chances in job placements??

It could. Depends on the nature of the conviction as compared to the job.

Hi,
As the previous answer stated, it could; And I would like to add, if it was a Felony conviction. Misdemeanors usually are not asked for on job applications.