Respiratory diseases, including asthma, chronic obstructive pulmonary disease (COPD), pulmonary fibrosis and lung cancer, impose a significant global health burden. Conventional treatments, such as corticosteroids, bronchodilators and antibiotics, often have limitations, including drug resistance, side effects and high costs. Phytochemicals derived from medicinal plants have gained attention as potential therapeutic agents due to their anti-inflammatory, antioxidant, bronchodilatory, mucolytic and immunomodulatory properties. This chapter explores the comparative efficacy of key phytochemicals, including polyphenols, terpenoids, alkaloids and saponins, in the management of respiratory diseases. Specific compounds such as quercetin, curcumin, eucalyptol and berberine have shown promise in mitigating airway inflammation, reducing oxidative stress and enhancing immune responses. Furthermore, the integration of phytochemicals with nanotechnology and conventional therapies is discussed to optimize their therapeutic potential. Challenges related to bioavailability, standardization and clinical validation are also highlighted. Advancing research on phytochemicals may lead to more effective and safer alternatives for respiratory health management.