This paper aims to shed some light on the drivers of (relatively) small-scale ethno-communal violence within an ethnically diverse state, by quantitatively examining the relationship between horizontal inequalities and ethno-communal violence. Specifically it addresses the complexity in assessing the effect of Horizontal Inequality on ethno-communal conflict in Indonesia. The paper examines the case of Indonesia around the time of the downfall of the New Order regime and the first years of the reformasi (roughly 1997-2003). Different HI indicators are constructed and a pooled time series cross-sectional probit regression is utilised, using deadly ethno-communal violence as a binary (dummy) dependent variable. The research measures HI indicators across five dimensions (health, employment, education, housing and network connectivity), which are further subdivided into access and achievement variables. Results show that while horizontal inequalities can be considered a determinant for ethno-communal conflict, there are marked differences in the society for different groups, in this case linguistic versus religious groups. Preliminary results show that a common basis is formed by horizontal inequalities in malnutrition and water source. A main driver of the ethno-religious estimations has been adult educational attainment, pointing out to a narrative where schooling – and the career chances that come with it – is something for the privileged groups, leading to frustration among the disadvantaged. This study adds to the existing literature on horizontal inequalities and conflict by building on previous studies and looking further at a broad range of horizontal inequality indicators within the diverse context of Indonesia. We reflect on the notion that there is not a single dimension with a clearly stronger explanatory strength than another. Rather, it is the combination of different facets of horizontal inequality that enables us to uncover the variation in the data.