Aim The present study aimed to identify the health needs of the hidden elderly in Hong Kong, and to investigate the impacts of pharmacist and nursing interventions on medication management and well‐being in hidden elderly. Methods Participants were recruited by social workers if they were aged 65 years or older; did not have normal social life and network; did not have family support; and were not linked to the existing network of community support. Pharmacists identified drug‐related problems. The health needs of participants were assessed by observations and interviews. Outcome measurements were scores of Morisky 8‐item Medication Adherence Scale and EuroQoL (Quality of Life) 5‐D Questionnaire. Results A total of 93 participants were recruited and 86 participants completed the study. The mean age was 81.46 ± 5.70 years, the mean number of chronic disease was 3.29 ± 1.45 and the mean number of chronic medications was 6.36 ± 2.96. The most commonly observed chronic diseases were hypertension, cardiac problems, diabetes, hyperlipidemia and arthritis. Drug non‐adherence and storage problems were found in 61.63% and 69.77% of participants. The mean total EuroQoL score increased by 1.05 (P ≤ 0.001). The mean Morisky score decreased by 0.61, signifying improvement of medication adherence (P < 0.001). Female sex (P = 0.045), polypharmacy with more than nine concurrent medications (P = 0.013), arthritis (P = 0.006) and drug storage problems (P = 0.002) were identified as factors associated with poor medication adherence. Conclusions The majority of hidden elderly suffered from multiple chronic diseases, and the prevalence of drug‐related problems was high. Pharmacist and nursing interventions improved drug‐related problems, drug compliance and quality of life in hidden elderly. Geriatr Gerontol Int 2013; ●●: ●●–●●.