Objective To investigate the correlation between potentially inappropriate medication (PIM) and decline of intrinsic capacity (IC) in the elderly inpatients. Methods A total of 215 elderly inpatients admitted to the Fu xing Hospital Affiliated to Capital Medical University from January 2022 to June 2022 were analyzed. The patients were divided into PIM group (125 cases) and non-PIM group (90 cases) according to the PIM categories for the elderly in China. The comorbidity, types of oral drugs, IC and other indicators of patients were recorded. SPSS statistics 23.0 was used to analyze the data. Independent sample t test, Mann-Whitney U test or Chi-square test was used for comparison between groups. Spearman correlation analysis was used to analyze the correlation between PIM and intrinsic capacity decline. Multivariate logistic regression was used to analyze the related risk factors of PIM. Results The patients were aged 60-109 (84.0±7.0) years, and 134 (62.3%) were males. The patients scored 2.0 (1.0,3.0) points for intrinsic capacity. Decreased intrinsic capacity was seen in 93.0% (200/215) patients, and decreased motor ability in 75.8% (163/215). Intrinsic capacity decline ≥ 3 accounted for 40.0% (86/215). The types of oral drugs ranged from 0 to 17, with 6.0 (3.0,8.0) types per person, and 63.3% (136/215) patients took more than 5 oral drugs. The rate of PIM use was 58.1% (125/215). Charlson comorbidity index (CCI) was 7.0 (6.0,9.0) points. Compared with the non-PIM group, the PIM group had significantly increased age, CCI, insomnia, constipation and choking, polypharmacy,more types of oral medication and IC score (P<0.05), but among the five scoring criteria of IC, exercise capacity decreased, the difference being statistically significant (P<0.05). Spearman correlation analysis showed that PIM was positively correlated with age, intrinsic capacity score, polypharmacy and CCI (r=0.167,0.205,0.468,0.214; P＜0.05). Multivariate logistic regression analysis showed that decreased IC score (OR=1.567,95%CI1.102-2.228; P＜0.05) was a risk factor for PIM after adjusting for age, gender, disease severity and polypharmacy. Conclusion Decreased IC is a risk factor for PIM in the elderly inpatients, and PIM should be screened in the elderly inpatients with decreased intrinsic capacity to reduce PIM use.