<p>Early detection of CSA risk in the family environment is a complex clinical and social challenge, and its success depends on various factors that fall under the scope of different disciplines. Nevertheless, we argue that social workers working on the front line of the child protection system have a key role to play in this process. We therefore undertook participatory research based on collaboration between a university research facility and local authorities of the state child protection system. On the basis of an assessment of 435 cases of children at risk, carried out by social workers from 50 local offices of child protection authorities in Slovakia, we tried to determine whether there is a significant difference between the initial estimate of their risk of CSA using standard heuristic assessment methods and the result of a subsequent objective assessment using a standardized tool. The main finding of the research is that, on average, 29% of the cases reviewed there was a significant underestimation of the risk of CSA in the initial assessment compared to the subsequent standardized measurement. We believe that the causes of underestimation of the situation of a child at risk of CSA are the over-formalization of tasks, bureaucratization and structural conditions of the profession in the child protection system, as well as the failing system of social worker education on a national scale. However, the consequences of underestimating the situation of a child at risk of sexual abuse in the family environment can be fatal for the child.</p>