Social motivations of young adolescents are strongly influenced by differing levels of social achievement goals, which in turn are affected by a number of factors. Specifying these factors, especially those effective on achievement, can help improve conditions for learning. A thorough approach would include a generalisable pattern of behaviour to offer global explanations in and out of classroom interactions. This study aimed at assessing the factorial validity and measurement invariance of Social Achievement Goals Scale (SAG) and its perception by students from low and high socio-economic status in an urban setting with a sample of 1643 middle school students. Confirmatory factor analyses and measurement invariance analyses across gender were performed and mean differences between low and moderate high socio-economic status were sought. Proposed factorial structure of the SAG measure was confirmed and measurement invariance results indicated that SAG was measuring the same construct in the same way for female and male students. Male students were found to have slightly stronger social development, social demonstration-approach, and social demonstration-avoid goals than their female counterparts. Moderate-high socio-economic status students had significantly higher social achievement goals than low socio-economic status students.