Introduction: The elderly's respiratory system suffers a progressive decrease in performance due to structural and functional changes. Among the structural causes, changes that occur in the lungs, rib cage and respiratory muscles are observed. In relation to physiological processes, there is a reduction in the compliance of the rib cage, accompanied by weakness of the respiratory muscles, impairing the effectiveness of coughing, predisposing to the retention of secretions and the development of bronchopulmonary infections. Objective: To evaluate the inspiratory and expiratory muscle strength of institutionalized elderly people. Methodology: Cross-sectional study, with quantitative analysis, with a convenience sample, carried out in a Long-Term Institution for the Elderly (ILPI) in the city of Lajeado, RS, Brazil. To measure the maximum inspiratory pressure (MIP) and maximum expiratory pressure (PEmax), an analogue manometer was used with a numeric scale for positive pressure (+120 cmH2O) and negative pressure (–120 cmH2O) with an interval of 4 cmH2O. Results: 12 elderly people participated (mean: 80.4 years; SD: 8.1), 7 women (58.3%) and 5 men (41.7%). The average length of stay in ILP was 2.6 years (SD: 2.1) and the average BMI was 26.2 kg/m2 (SD: 4.6). There was a negative correlation between age versus MIP and MEP, as with increasing age there was a decrease in MIP and MEP. Conclusion: MEP and MIP are below expectations for the variables age and sex by 100% and 91.7%, respectively, in the elderly participants in the present study.