Neurodevelopmental disorders are a set of disorders that negatively affect the acquisition of skills in a variety of developmental domains, including motor function, learning, socialization, language and cognition. However, there is no information available on the standard of living of Ethiopian primary caregivers of children and adolescents with neurodevelopmental disorders. Therefore, this study aimed to assess the quality of life (QOL) and associated factors among primary caregivers of children and adolescents with neurodevelopmental disorders in Addis Ababa, Ethiopia. A cross-sectional study was conducted during 1-30 May 2022. Systematic random sampling was used to obtain 352 samples. QOL was measured using the WHO Quality of Life Brief. The gathered information was coded, entered into EpiData 4.6.0.2 and analyzed with SPSS version 26. Multiple linear regression analysis was used to identify the correlates of QOL and the strength of the correlation was measured by β coefficient with 95% CI. The mean score of the overall QOL was 62.61 with a SD of 5.17. The mean (±SD) scores for the physical health, psychological, environmental and social relationship domains of primary caregivers were 57.36±9.98, 66.98±9.39, 66.06±12.91 and 60.02±9.14, respectively. Age was significantly associated with physical domain (β=-0.25, 95% CI -0.43 to -0.07) and with environmental domain (β=-4.57, 95% CI -9.06 to -0.09). Being divorced/widowed was negatively associated with psychological health (β=-2.99, 95% CI -5.82 to -0.17) and social health (β=-0.62, 95% CI -1.33 to -0.10). The presence of medical illness was negatively associated with the physical health domain (β=-4.32, 95% CI -7.64 to -2.91) and the environmental domain (β=-3.11, 95% CI -5.71 to -0.51). Poor social support was negatively associated with psychological health (β=-3.25, 95% CI -5.89 to -0.61) and the social health domain (β=-3.39, 95% CI -11.3 to 4.6), and moderate social support (β=8.62, 95% CI 3.15 to 14.09) was positively associated with physical health. Depression (β=-6.32, 95% CI -11.96 to -0.67) and anxiety (β =-3.07, 95% CI -5.80 to -0.34) were negatively associated with physical health and the psychological health domain, respectively. The findings from this study indicate that all dimensions of QOL of primary caregivers of children and adolescents with neurodevelopmental disorders in this study setting were compromised. Being divorced or widowed, lack of formal education, age, average monthly income, poor social support, depression, anxiety and the presence of medical illness were factors associated with QOL in all domains. This requires integrating a bio-psychosocial perspective, a positive mental health strategy and pharmaceutical therapies to enhance QOL for caregivers of children and adolescents with neurodevelopmental disorders.