Drought stress is a major factor limiting crop yield. Nitric oxide (NO) is an important signal molecule that plays diverse roles in plant growth and defensive responses. However, little is known about the role of NO produced by plants under drought stress. In this study, we investigated the effects of sodium nitroprusside (SNP), an NO donor, on polyethylene glycol (PEG)-induced drought stress in bananas. PEG treatment alone or in combination with SNP and 2-(4-carboxyphenyl)-4,4,4,5,5,-tetra-methyllimidazoline-1-oxyl-3-oxide (cPTIO; an NO scavenger) was evaluated. PEG treatment significantly reduced plant growth. However, the application of SNP significantly alleviated the inhibiting effect of the drought stress in a dose-dependent manner. In contrast, the cPTIO at a concentration equimolar to the SNP reversed the effect, suggesting that the promotive effects may be due to NO itself. We then applied a gel-based proteomic approach to investigate the drought responses of bananas to define the role of NO. Ten proteins from 26 protein spots were identified using LC-MS/MS analysis. The majority of these proteins were stress-response and carbohydrate and energy metabolism-related proteins. These findings suggest that exogenously applied NO can appreciably improve drought tolerance in bananas, affirming its role in this stress-survival mechanism.