Students’ attitude towards mathematics is affected by factors such as parental influences, teacher affective support and classroom instruction. The purpose of this research was to examine the inter-relationships between these factors and effects on attitude towards mathematics using a partial least squares-structural equation modeling approach. A survey was carried out with a sample of 318 Form Four students from Sabah, Malaysia. The questionnaire consists of four scales: Perceived Parental Influences, Teacher Affective Support, Classroom Instruction and Attitude towards Mathematics. IBM SPSS 19.0 and Smart PLS 2.0 were used to analyze the measurement and structural models. The results showed that with the exclusion of some indicators from the scales, the measurement models showed acceptable reliability and validity. The structural model has moderate predictive relevance but the inter-relationships of the constructs in the structural model were significant. Teacher affective support and classroom instruction predict attitude towards mathematics more than parental influences.