Teaching responsive to the needs of students with learning disabilities (LD) can be provided through understanding students' conceptions and their ways of learning. The current research, as a case study based on qualitative design, aimed to investigate the conceptions of students with learning disabilities with regard to the different representations of length (width, length, and height). The participants were 3 Turkish students at 4th, 5th and 6th grades recognised by the local Counselling and Research Centre (CRC) as having learning disabilities. The data were collected through semistructured and task-based interviews, and analysed via content analysis method. The findings suggest that width, length, and height conceptions of students with learning disabilities are influenced by their conceptions of length and visual-spatial abilities.