In the aftermath of the fall of Ben Ali’s regime, Islamic associations mushroomed as new “mobilizing agencies” (Norris, 2002) thanks to a more favourable socio-political environment. There is an academic literature, implicitly stemming from Putnam’s theory on social capital, that highlights the capacity of associations with religious references to bridge social cleavages, contributing to a dense and vibrant social infrastructure (Clark, 2004; Harmsen; 2008). After the Arab uprisings, new theories emerged to capture these forms of civic engagements. Merone and Soli focused on Tunisian Islamic associations as agencies of a “social counter-power” (Merone and Soli, 2013), while Chalcraft spoke of the success of “horizontalism” to understand the "Egyptian revolutionary process" (MERIP, 2011). This paper investigates the emergence and evolution of a dense network of Islamic charitable and cultural associations in Tunisia since 2011 as new pivotal actors of a changing civil society, with a focus on the capacity to maintain new social links. How have religious grass-roots associations framed social development? How do they facilitate social and political mobilization through the building of horizontal networks? Does their action build only within, or favour only, their constituency or does it build links beyond the Islamic constellation? Based on interviews done in 2015 and 2016 in the centre and south of Tunisia (Qayrawan, Sfax and Medenine), this study then assesses the possibility of “horizontalism” to remain a structuring principle. This acquires more relevance in a post revolutionary Tunisia characterized by a high politicization of civil society actors and a substantial flow of foreign aid. Two factors which generate, by themselves, new vertical internal and external hierarchies and therefore complicate the notion of horizontal linkages.