Objectives This study aimed to evaluate the efficacy of a supplement product containing proteoglycan extract from salmon nasal cartilage on knee movement and walking function in healthy adults. Methods A randomized, double-blind, placebo-controlled, parallel-group study was conducted in 54 participants aged 43 to 73 years with anxiety about falling. Participants were randomly assigned to receive a test product containing proteoglycan or placebo for 12 wk. Primary endpoints were evaluated by Timed Up and Go (TUG) test and 6 min walk test. Secondary endpoints were evaluated by the score of Japanese Knee Osteoarthritis Measure (JKOM), Tinetti's Fall Efficacy Scale (FES), 2 step test, knee extension muscle strength and 30 s chair stand test. Results In anal. of the total evaluable population, there was no significant change in primary and secondary outcomes between test product group and placebo group. However, anal. of locomo level 1 participants revealed that significant decrease of time taken to stand and pre-turn time on TUG test in the test product group compared with the placebo group. In addition, the score of "Reach into cabinets or closets?" on FES in test product group was signifi-cantly lower compared with the placebo group. Conclusions These results suggest that the ingestion of proteoglycan extract from salmon nasal cartilage improves knee movement and walking function in healthy adults whose mobility is beginning to decline with aging.