Objectives – The aim of the present study was to determine the impact of commonly used and potentially detrimental drugs on rehabilitation results and to clarify their role as prognostic factors. Material and methods – The study included 154 patients admitted to a rehabilitation hospital for sequelae of a first stroke. Multivariate analyses were performed using effectiveness of treatment, evaluated by both the Barthel Index (BI) and the Rivermead Mobility Index (RMI) and low response on both of these indexes as dependent variables. Independent variables were medical, demographic and pharmacological factors. Results – The use of detrimental drugs was negatively associated with effectiveness on both BI and RMI. Severity of stroke (Canadian Neurological Scale score at admission) and hemineglect were the other negative prognostic factors that significantly entered the analyses. On the other hand, the presence of Broca's aphasia positively influenced the recovery, essentially due to prolonged length of stay. The presence of detrimental drugs and hemineglect were associated with a higher risk of low response on both BI and RMI. Conclusion – These findings confirm that the use of some drugs can influence rehabilitation results. Therefore, the choice of pharmacological treatment of stroke patients should be carefully evaluated by considering the potential detrimental effects of some drugs commonly used for the treatment of coincidental medical conditions.