<p>Untreated urban wastewater is a major driver of aquatic ecosystem degradation, yet its impacts on saline wetlands, notably Sabkha ecosystems, remain poorly understood. We investigated the fine-scale responses of benthic macroinvertebrates to wastewater discharge in Sabkhat El Mahmal, a Mediterranean Sabkha in northeastern Algeria. During monthly surveys over a one-year period, we concurrently measured physicochemical and bacteriological water parameters and sampled benthic macroinvertebrates at six stations along a pollution gradient, followed by community analyses using multivariate and indicator-species approaches. Urban wastewater inputs induced localised desalination, elevated phosphate concentrations, and increased faecal coliform counts, leading to significantly degraded water quality near the discharge outlet. While taxonomic richness, abundance, and diversity did not vary significantly among stations, community structure shifted markedly. Polluted stations were dominated by pollution-tolerant taxa such as Chironomidae (Diptera) and <i>Corixa</i> (Hemiptera, Corixidae), whereas less impacted stations were characterised by <i>Cordulegaster</i> (Odonata, Cordulegastridae). These results demonstrate that urban wastewater alters community structure through biotic homogenisation and the replacement of sensitive taxa with tolerant ones, without necessarily reducing coarse diversity metrics. Our findings provide empirical evidence of wastewater impacts in Mediterranean Sabkhas and underscore the urgent need for improved wastewater management to safeguard these ecologically valuable saline wetlands.</p>