Background <p>This study examines thoracic surgical nurses’ Knowledge-Attitude-Practice (KAP) regarding postoperative pulmonary rehabilitation to improve patient recovery and reduce complications after thoracic surgery.</p> Methods <p>This cross-sectional study was conducted among thoracic surgical nurses from 7 tertiary hospitals in Beijing between April 8 and April 30, 2024, using a self-administered questionnaire.</p> Results <p>A total of 238 valid questionnaires remained. Of these, 191 (80.25%) were female, and 169 (71.01%) had received training in perioperative pulmonary rehabilitation. The mean knowledge, attitudes and practices score were 10.45 ± 3.98 (possible range: 0–34), 33.31 ± 6.50 (possible range: 8–40), and 31.65 ± 6.52 (possible range: 8–40), respectively. The mediation analysis revealed that gender (β = 1.731, <i>p</i> = 0.021), age (β = 0.161, <i>p</i> = 0.018), hospital level (β = -0.943, <i>p</i> = 0.008), education (β = 1.031, <i>p</i> = 0.031), and years of working (β = -1.127, <i>p</i> = 0.006) had significant direct impacts on knowledge. Knowledge itself was a significant predictor of attitudes (β = 0.777, <i>p</i> = 0.009) and directly influenced practice as well (knowledge: β = 0.327, <i>p</i> = 0.010; attitudes: β = 0.342, <i>p</i> = 0.010). Concurrently, gender (β = 1.346, <i>p</i> = 0.012), age (β = 0.125, <i>p</i> = 0.011), hospital level (β = -0.733, <i>p</i> = 0.006), education (β = 0.801, <i>p</i> = 0.021), and working years (β = -0.876, <i>p</i> = 0.005) indirectly influenced attitudes. Additionally, gender (β = 1.732, <i>p</i> = 0.009), age (β = 0.095, <i>p</i> = 0.007), and knowledge (β = 0.266, <i>p</i> = 0.011) indirectly impacted practice.</p> Conclusions <p>Thoracic surgical nurses exhibit a solid foundation in knowledge and positive attitudes towards postoperative pulmonary rehabilitation, influenced by demographics and education. Targeted training programs are recommended to improve their knowledge, potentially enhancing patient outcomes in recovery.</p>