This study empirically explored the effect of financial deepening indicators on the performance of pharmaceutical firms in Nigeria. The study used annual time series secondary data extracted from annual account and financial statement of the selected manufacturing firms for the periods of 2006-2016. The financial deepening indices used were ratio of broad money supply to GDP (M2/GDP); ratio of credit to private sector to GDP (CPS/GDP); and market capitalization (MCAP) as explanatory variables while the response variable was earnings per share (EPS) of pharmaceutical firms in Nigeria. The study adopted ex-post facto research design and employed Ordinary Least Squares (OLS) panel regression analysis techniques. Electronically, the data analysis was aided by Eviews 9.0 econometric package. The findings revealed that financial deepening has a significant positive influence on earnings per share (EPS) of pharmaceutical firms in Nigeria. The implication of the finding is that financial deepening helps pharmaceutical firms’ growth in Nigeria. The study therefore recommended that financial deepening should be encouraged since it triggers the performance of pharmaceutical firms and overall economic growth of Nigeria.