This study purports to bridge the gap in research directed at people with Low Functioning Autism (LFA) by exploring if sensory discrimination ability can be used to assess cognitive functioning in children with LFA. The study was done in two phases: (i) a pilot phase (with 4 male participants; mean age = 3 years 6.5 months)--which tried to validate whether the paradigm of 'visual paired comparison' procedure (Fantz, Science, 146, 668-670, 1964) can be effectively used in measurement of perceptual judgment of LFA, diagnosed on the basis of 'Autism Diagnostic Checklist' by Banerjee ("Indian Journal of Clinical Psychology," 34, 83-93, 2007). (ii) A main phase (with 20 participants; male = 18, female = 2; mean age = 4 years 8 months)--which determined sensory discrimination ability in LFA in the auditory and visual modality and related the findings with the sensory threshold of the children by using 'The Sensory Profile' (Kumar and Banerjee, "Development of sensory integration therapeutic module for autism and its effect on some functional areas of autism." Unpublished Ph.D Thesis, 2011). The results reveal that the 'Visual Paired Comparison' paradigm can be used as a tool to discern sensory discrimination ability in children with Low Functioning Autism. Also, sensory discrimination can be used to differentiate the cognitive ability of children with Low Functioning Autism. The behavioural repertoire of sensory discrimination is associated with the sensory threshold of the participants.