The development of sustainable process and products have been encouraging the exploitation of cellulose as a resource. Banana peel is rich in cellulose, a renewable source that has potential to be used in a variety of friendly applications. The vegetal fibers, in nanometric size, have been explored as an alternative to reinforce biopolymeric matrices, since they have potential to improve thermal stability, mechanical and barrier properties. In this research, cellulose nanofibers (CNFs) have been isolated from banana peel bran by acid hydrolysis (H2SO4). The effect of the use of different acid concentration (0.1 %, 1.0 % and 10.0 %) (N) and mechanical treatment (high-pressure homogenization) (NM) was evaluated. Mechanical spectra of the aqueous cellulose nanofibers suspensions (1.0% w/w) were determined by scanning frequency in the range of 0.1 - 100 rad/ s, at constant strain and temperature of 25 °C using a rheometer Anton Paar Physica MCR 301. All CNFs obtained, independently of used treatment, showed gel-like behavior, with G´(storage modulus) > G´´ (loss modulus). Increasing the acid concentration and the use of the mechanical treatment, increases the storage and loss modulus of the CNFs. This effect can be explained because the use of treatments, at higher acid concentrations, caused a decrease in CNFs length (N0.1 = 619.57, N1 = 559.10, N10 = 437.83, NM0.1 = 507.03, NM1 = 326.33, and NM10 = 310.77 nm) and CNFs diameter (N0.1 = 4.65, N1 = 4.11, N10 = 3.72, NM0.1 = 3.53, NM1=3.47, and NM10 = 2.89 nm). Besides, the used treatments caused a higher fibrillation of the CNFs suspension. Thus, the surface area was increased facilitating the physical interactions between CNFs, which causes an increase in gel strength. The nanoparticles isolated from banana peel have potential mechanical strength properties and seem to be very promising as reinforcing agent in high-performance composites.