This study probes students' beliefs about nature of mathematics, difficulty in learning mathematics sourcing from these and their influence on achievement in mathematics. Questionnaire survey on 458, 9th standard students randomly selected from schools of Malappuram district elicited data on nature of school mathematics and difficulty arising out of it. Test on Achievement of Prerequisites in Mathematics on Basic operations, Rational numbers and exponents, Geometry, Algebra, and Daily Mathematics was conducted. Overall achievement in mathematics and achievement in its component areas are influenced more by difficulties arising from nature of content than teaching learning process and learning technique. Achievement in daily mathematics is influenced by difficulties arising out of teaching learning process. Findings implies that special nature of mathematics is to be considered in adapting teaching learning to reduce difficulties in learning it.