22q11.2 deletion syndrome (22q11DS) is a genetic condition associated with a markedly increased risk for psychosis. Psychotic experiences are classically evaluated by clinical interviews that give little information about these symptoms' fluctuation in daily-life. The current study, conducted by aims to investigate these phenomena using the Ecological Momentary Assessment (EMA), a structured diary technique that collects real-life measures in the everyday-life context, and to examine how these manifestations relate to a gold standard semi-structured assessment of psychotic experiences. Eighty-six individuals with 22q11DS as well as healthy controls (HC) aged 11-27 years were recruited. They completed a 6-day EMA protocol assessing momentary psychotic experiences as well as positive and negative affect. The presence of (attenuated) psychotic symptoms was assessed in 22q11DS participants with the SIPS interview. Participants with 22q11DS reported more intense (p = .005) and more frequent (p = .006) momentary psychotic experiences than HC. Significant associations between negative affect and momentary psychotic experiences were observed in both groups (p = .001). In participants with 22q11DS, more intense (p = <.001) and more frequent (p = <.001) momentary psychotic experiences measured by EMA were associated with the severity of SIPS positive symptoms. Participants with 22q11DS reporting at least attenuated positive symptoms of psychosis on the SIPS had more intense (p = .027) and more frequent (p = .023) momentary psychotic experiences than participants with 22q11DS without psychotic symptoms. This study highlights the validity of EMA to assess psychotic experiences in the context of daily-life and sets correspondence between EMA and the SIPS. Furthermore, it expands our current understanding of the associations between mood and psychotic experiences.