The study investigates the effect of working capital management on economic growth and development, with emphasis from listed conglomerates firms in Nigeria. Four objectives were employed with coverage of a ten-year period spanning from 2011 to 2020. Secondary data were used in the study with total population based on five (5) conglomerate firms listed on Nigerian Stock Exchange. The tests of the four null hypotheses were carried out using spearman rank correlation analysis and also employed panel least square (POLS) regression analysis. The result of the analyses revealed the following: Cash conversion cycle (Random effect = -0.03 (0.002)) has a negative significant influence on firm profitability. Inventory period (Random effect = 0.02 (0.262) has a positive insignificant influence on firm profitability. Current ratio (Random effect = 15.55 (0.002) also has positive but significant influence on firm profitability. Quick ratio (Random effect = -12.45 (0.035) has a negative significant influence on firm profitability. The study concludes that cash conversion cycle and quick ratio tend to decrease firm profitability while we provide evidence that current ratio improves firm profitability. The study recommends, among others, that Management of these conglomerates companies should advocate for policies that will enhance swift conversion of inventory to cash to improve firm profitability for economic growth and development in Nigeria.