Chronic heart failure (CHF) and chronic obstructive pulmonary disease (COPD) frequently coexist, significantly impacting health-related quality of life (HRQoL). This study evaluated HRQoL in patients with CHF, COPD, or both, three months post-COVID-19 discharge using EQ-5D and KCCQ questionnaires to guide targeted healthcare interventions. We conducted a cross-sectional study at “Victor Babes” Hospital in Timisoara, enrolling 180 patients who had recovered from COVID-19 (60 in each group including CHF, COPD, and both conditions). HRQoL was assessed via EQ-5D and KCCQ. Significant disparities in HRQoL measures were noted across the groups. Patients with both CHF and COPD reported the worst outcomes, especially in terms of hospital stay lengths due to COVID-19 (11.63 days) and initial oxygen saturation levels (88.7%). HRQoL improvements from discharge to three months post-discharge were significant, with EQ-5D mobility scores improving notably across all groups (CHF and COPD: 2.87 to 2.34, p = 0.010). KCCQ results reflected substantial enhancements in physical limitation (CHF and COPD: 38.94 to 58.54, p = 0.001) and quality of life scores (CHF and COPD: 41.38 to 61.92, p = 0.0031). Regression analysis revealed that dual diagnosis (CHF and COPD) significantly impacted usual activities and quality of life (β = −0.252, p = 0.048; β = −0.448, p = 0.017), whereas the initial severity of COVID-19 was a significant predictor of worse HRQoL outcomes (β = −0.298, p = 0.037; β = −0.342, p = 0.024). The presence of both CHF and COPD in patients recovering from COVID-19 was associated with more severe HRQoL impairment compared with either condition alone. These findings emphasize the need for specialized, comprehensive post-COVID-19 recovery programs that address the complex interplay among chronic conditions to optimize patient outcomes and enhance quality of life.