The study provides a holistic view of how employees‟ career advancement can affect organizational effectiveness among selected deposit money banks in Nigeria. The specific objective is to determine the relationship between career advancement and organizational effectiveness in the Nigerian deposit money banks. Primary data was collected from a total of seven (7) banks from existing twenty one (21) licensed banks by Central bank of Nigeria (CBN) through structured questionnaire to elicit information on career development. Data collected were analyzed using both descriptive statistics to determine the relationship between respondents socio-economic characteristics and organizational effectiveness while inferential statistics of Pearson Product Moment Correlation coefficients (PPMC) was employed to analyze the relationship between the variables of career advancement and organizational effectiveness respectively. Findings revealed that employee career advancement in the organization exert a great influence on the operations of deposit money banks in Nigeria, and as such banks management should invest in employees‟ development to stem employee turnover and improve productivity.