To improve equity in the provision of health care and provide risk protection to poor households, low-income countries are increasingly moving to social health insurance. Using data from a household survey of 3301 households conducted in 2009 this study aims to evaluate equity in enrollment in the National Health Insurance Scheme (NHIS) in Ghana and assess determinants of demand across socio-economic groups. Specifically by looking at how different predisposing (age, gender, education, occupation, family size, marital status, peer pressure and health beliefs etc) enabling (income, place of residence) need (health status) and social factors (perceptions) affect household decision to enrol and remain in the NHIS. Equity in enrollment is assessed by comparing enrollment between consumption quintiles. Determinants of enrolling in and dropping out from NHIS are assessed using a multinomial logit model after using PCA to evaluate respondent's perceptions relating to schemes, providers and community health 'beliefs and attitudes'. We find evidence of inequity in enrollment in the NHIS and significant differences in determinants of current and previous enrollment across socio-economic quintiles. Both current and previous enrollment is influenced by predisposing, enabling and social factors. There are, however, clear differences in determinants of enrollment between the rich and the poor. Policy makers need to recognize that extending enrollment will require recognition of all these complex factors in their design of interventions to stimulate enrollment.