The effects of oral supplementation with a Ganoderma lucidum polysaccharide (GLP) formula on immune recovery, fatigue alleviation, and sleep quality in patients after laparoscopic surgery were investigated. A prospective, randomized, doubleblind, placebo-controlled, single-center clinical trial was conducted. A total of 78 postoperative patients were randomly assigned to a placebo group (n=38) or a GLP group (n=40) and received placebo or the GLP formula, respectively, for 30 consecutive days. The results showed that, compared with those of the placebo group, the GLP group exhibited significant increases in total protein (from 60.69 g•L-1 to 69.17 g•L-1), albumin (from 33.47 g•L-1 to 41.27 g•L-1), and prealbumin (from 196.31 mg•L-1 to 291.21 mg•L-1) (P<0.05). Regarding immune function, the percentages of CD3+ cells, CD3+/CD4+ cells, and CD3+/CD8+ cells increased from 56.96% to 65.42%, from 41.64% to 51.77%, and from 18.75% to 27.40%, respectively. In addition, serum IgA and IgG levels increased from 2.02 to 2.87 g•L-1 and from 9.04 to 12.74 g•L-1, respectively, all of which were significantly higher than those in the placebo group (P<0.05). Furthermore, the levels of inflammatory cytokines TNF-α and IL-6 were significantly reduced in the GLP group (P<0.05). The fatigue score decreased from 41.03 to 27.20, while the sleep quality index increased from 61.38 to 84.50, both showing significant improvement compared with the placebo group (P<0.05). Overall, the GLP formula demonstrated beneficial effects on nutritional status, immune regulation, inflammation reduction, fatigue alleviation, and sleep quality during postoperative rehabilitation. These results provide clinical evidence supporting the use of GLP formula as a nutritional intervention to promote recovery in patients after laparoscopic surgery.