In Uganda, there is limited adoption of pharmaceutical care in hospitals due to pharmacist shortages and limited collaboration among healthcare professionals. Intern pharmacists are deployed annually to assist in patient care to address pharmacist shortages. Evaluate intern pharmacist's extent of involvement in pharmaceutical care activities, assess facilitators and barriers, and explore healthcare professionals' perceptions, attitudes, and opinions on implementation of pharmaceutical care. A mixed-method concurrent study was carried out for four months. We conducted an online survey among 107 intern pharmacists from 26 hospitals, including National Referral, Regional Referral, Private Not-For-Profit, and General hospitals; predictors of extent of involvement were identified using linear regression models, using STATA 14. 24 key informants (nurses, prescribers, pharmacists) from five hospitals were interviewed; themes were developed using a deductive thematic analysis approach. Intern pharmacists had a median (Interquartile range[IQR]) age of 25 years (25-27) and 74.7% were male. About half (54.1%) of key informants were female and had a median (IQR) of 10 years (4.0-15.5) of professional experience. Interns focused on patient counseling, lacked documentation, and showed positive attitudes, and knowledge. Key informants supported implementation, but prescribers expressed dissatisfaction with interns' performance. Enhancing pharmacy internship and training through developing policies and guidelines on pharmaceutical care practice, improving working conditions, and mentorship can address gaps impeding pharmaceutical care implementation by intern pharmacists.