The aim of the study was to investigate the posture and musculoskeletal discomfort of secondary school students while working at computers in school. Students (n = 40) were observed while working at a computer during their designated computer class. The Rapid Upper Limb Assessment Tool (RULA) was used to assess posture. A Body Discomfort Chart (BDC) and Visual Analogue Scale (VAS) were used to record the area(s) and intensity of musculoskeletal discomfort, if any, experienced by the students at the beginning and end of the computer class. None of the students' posture was in the acceptable range (Action Level 1) according to RULA. The majority (65%) were in Action Level 2, 30% were in Action Level 3, and 5% were in Action Level 4. There was a statistically significant increase in reported discomfort from the beginning to the end of the computer class. Longer class length (80 minutes) did not result in greater reporting of discomfort than shorter class length (40 minutes).