Objective: To assess the impact of breathing exercise which was introduced as a method of play therapy to measure the cardiopulmonary parameters among children (3-12 years) with LRTI and to determine the association between the socio-demographic variables of children with group after intervention. Method: Evaluation approach was adopted and the study was based on the conceptual framework of Pender’s health promotion revised model. A quasi-experimental control group design was adopted. The sample of 40 children was divided into 20 in each experimental and control group. Data collected by using socio-demographic variables and observational checklist. The tool was validated by verifying it with different experts from professionals of medical science, nursing science, and statistician. Result: There was a maximum of samples (65%) were of 3-5 years of age and (68%) were male. The majority of samples (40%) were from rural area. With regards to diagnosis and immunization status, majority samples (60%) were of bronchitis, and (70%) were fully immunized respectively. There was a significant difference after the administration of the intervention of cardiopulmonary parameters in the interventional group. The post-test of respiration rate, mean ± SD (35.30±4.82) was less than pre-test respiration mean ± SD (38.30±4.70), and ‘t’ =9.57 was revealed extremely statistically significant at P <0.00001. The post-test plus rate mean ± SD(122.60±5.62) is less than the pre-test pulse mean ± SD (128.10±6.62), and ‘t’ =15.63 was revealed extremely statistically significant at P<0.00001. The post-test systolic BP mean ± SD (89.70±7.54) is less than the pre-test systolic BP mean ± SD (92.40±7.12), and ‘t’ =7.42 was recorded extremely statistically significant at P<0.00001 and the post-test diastolic BP mean ± SD (61.10±3.06) is less than the pre-test diastolic BP mean ± SD (63.20±3.25), and ‘t’ =6.84 was recorded to be extremely statistically significant at P<0.00001. The post-test chest expansion mean ±SD (51.60±2.51) was greater than the pre-test chest expansion mean ±SD (50.10±2.54), and the ‘t’ =16.97 was revealed to be extremely statistically significant at P<0.00001. Conclusion: In the present study there was no association between cardiopulmonary parameters with selected demographic variables such as age, gender developmental age, area of residence, diagnosis, and immunization status after the therapeutic intervention. The present study can be implicated in the field of nursing in specific areas of clinical practice, nursing education, administration, and research.