Chronic respiratory diseases (CRDs) pose a serious public health issue, affecting social functioning and psychological well-being and leading to a deterioration in the quality of life. The aim of this study was to assess the quality of life of patients with CRDs and determine the factors associated with their impairment in Morocco. A cross-sectional study was conducted in the Pulmonology Department of the Hassan II University Hospital in Fez in 2021. Data collection was carried out using an anonymous questionnaire containing sociodemographic, clinical, and therapeutic information. We employed the Moroccan version of the 12-item short-form (SF-12) scale to assess the mental and physical quality of life of patients. Bivariate analysis was performed to investigate the association between various factors and quality of life, using tests appropriate to the types of variables studied. Subsequently, multivariate analysis through multiple linear regression was employed to determine factors associated with quality of life, taking into account confounding factors. The threshold for inclusion in the model was set at 20%. Significant associations are presented as β values along with their 95% confidence intervals (CI). Our study included 209 patients, with 50.7% being female and 74.2% aged over 50 years. The most frequent clinical symptom was coughing. The average physical quality of life was estimated at 34.45±13.78, and the mental quality of life was 33.72±19.79. Multivariate analysis revealed that the deterioration of physical quality of life was associated with marital status (single) [β=-6.84; 95% CI (-11.43; -2.25); p=0.004], stage II dyspnea on the Modified Medical Research Council scale [β=-4.94; 95% CI (-9.41; -0.52); p=0.029], and the presence of cyanosis [β=-9.65; 95% CI (-15.64; -3.67); p=0.002]. The factors negatively associated with mental health in our patients were age ≥50 [β=-7.84; 95% CI (-15.05; -0.62); p=0.033], marital status (single) [β=-7.81; 95% CI (-15.14; -0.48); p=0.037], and presence of cyanosis [β=-10.70; 95% CI (-20.08; -1.32); p=0.026]. The SF-12 calculation reflected an impairment in the quality of life of patients with CRDs. It is imperative to integrate the assessment of quality of life into the management strategy for this pathology.