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• PCR assays were designed for the three genera of Microviridae. • Microviridae (genome and infectious) were systematically detected in wastewater. • Microviridae represent 10 % to 30 % of infectious somatic coliphages in wastewater. • In case of UV tertiary treatment, the inactivation reached 4 log 10. • Microviridae inactivation was similar to that of other somatic coliphages. Somatic coliphages (SC) and F-specific RNA coliphages (FRNAPH) have been included in regulations or guidelines by several developed countries as a way of monitoring water safety and the microbiological quality of shellfish harvesting waters. SC are highly diverse in their morphology, size and genome. The Microviridae family contains three genera of phages (Alphatrevirus, Gequatrovirus , and Sinsheimervirus), all having a capsid of similar morphology (icosahedral) and size (25–30 nm in diameter) to that of common pathogenic enteric viruses. Three PCR assays specific for each genus of Microviridae were designed to study these phages in raw and treated wastewater (WW) in order to gain knowledge about the diversity and prevalence of Microviridae among SC, as well as their inactivation and removal during WW treatments. Among the four wastewater treatment plants (WWTPs) monitored here, two WWTPs applied disinfection by UV light as tertiary treatment. First, we noticed that Microviridae represented 10 to 30 % of infectious SC in both raw and treated WW. Microviridae appeared to behave in the same way as all SC during these WW treatments. As expected, the highest inactivation, at least 4 log 10 , was achieved for infectious Microviridae and SC in both WWTPs using UV disinfection. PCR assays showed that the highest removal of Microviridae reached about 4 log 10 , but the phage removal can vary greatly between WWTPs using similar treatments. This work forms the basis for a broader evaluation of Microviridae as a viral indicator of water treatment efficiency and WW reuse. [Display omitted] [ABSTRACT FROM AUTHOR]