Aims of the study was to analyze the immediate impact of TBT on the evaluation parameters of the respiratory system in brazilian schoolchildren. This is a randomized clinical trial, with cross-sectional and before-after design, including 7-14 y.o. children without respiratory diseases. Methods used to conduct the study was to IOS, plethysmography and TBT. IOS and plethysmography were conducted before (T0) and immediately after (T1) each of the 3 TBT previously randomized. TBT included soap bubble toys (SB), party blowers (PB) and balloons (BL). Results of the study: 71 children (40 girls; mean age: 9.70 ± 2.12 years) participated in the study. When comparing T0 and T1, the impact of SB as 1stTBT were increased specific airway resistance (sRaw) and airway resistance (Raw), as well as less negative means of (reactance area) AX (p=0.034). As 2ndTBT, it showed lower values of (expiratory reserve volume) ERV and Gaw (p<0.05) and increased volume as percentage of total lung capacity RV%TLC and residual volume (RV) (p<0.05). As 3rdTBT, SB increased the resistances sRaw and total resistance at 5 hertz (R5), respiratory impedance (Z) and resonance frequency (Fres) (p<0.05). As 1stTBT, PB promoted an increase of R5 (p=0.045) and as 2ndTBT, an increase of Gaw (p=0.001). As 3rdTBT, PB increased Z, R5, Fres and AX (p<0.005). BL as 2nd and 3rdTBT increased R5, Fres and AX. As 2ndTBT, BL also increased Z, RV%TLC and IC (p<0.005) and decreased Gaw (p=0.001). Conclusions drawn from the study and clinical implications was to TBT produced an immediate impact on parameters for the assessment of respiratory mechanics and pulmonary function in schoolchildren. Use of TBT proved to be an important physiotherapeutic resource and resulting in potentially positive changes in the respiratory system in healthy schoolchildren.