The study identified the various strategic planning practices adopted by Nigerian banks and also examined the impacts of Strategic Plans on Corporate Performance. Primary data was used for the study. Lagos metropolis was used as the area of the study because 20 banks out of 21 post consolidated banks have their head offices in Lagos. Ten banks listed on the Nigerian stock exchange market with stable corporate identity were selected out of 21 Deposit Money Banks in Nigeria using purposive sampling technique. 200 senior staff of banks in the Nigerian banking industry was used as the population. Sample was selected using multi-stage sampling technique. Ten senior managers of the selected banks who are involved in strategic planning decision and coordination of resources in the banks were selected using purposive sampling techniques. Thus, the sample size for the study was 100 respondents. A well-structured questionnaire was administered to the respondents. Data was analysed using descriptive and inferential statistics. The findings of the study revealed that the strategic planning practices adopted by Nigeria banks included environmental scanning (73%), strategy formulation (83.2%) and feedback and evaluation (65%). It also revealed that strategic planning proxied by environment by environmental scanning (t=4.624, p< 0.05); strategy formulation (t=3.000, p< 0.05); feedback and evaluation t=2.019, p< 0.05) had significant effect on organisational performance. The study concluded that strategic planning if properly integrated by Nigerian banks could make significant improvement on their performance in the industry.