The role of the occupational therapist working in the school system is to facilitate a student’s task performance or ability to do purposeful and meaningful activities so that the student benefits from the educational experience. To fulfill this role, occupational therapists need assessments that address functional performance issues in the classroom and provide information for effective programming and consultation. The School Version of the Assessment of Motor and Process Skills (School AMPS) is an observational evaluation of functional skills in the classroom. Common classroom activities are observed to assess a child’s school motor and school process skills. This study examined the validity of the School AMPS by comparing it to the Peabody Developmental Motor Scale–Fine Motor (PDMS-FM), a common assessment used in local area school districts in Edmonton, Alberta. Results show a higher correlation of the PDMS-FM with the motor scale of the School AMPS than with the process scale of the School AMPS, which was expected. The School AMPS appears to be a promising instrument for measuring the constructs of school motor and school process skills within a naturalistic setting.