BACKGROUND:During hospitalization, stroke patients are bedridden due to neurologic impairment, leading to loss of muscle mass, weakness, and functional limitation. There have been few studies examining respiratory muscle strength (RMS) in the acute phase of stroke. OBJECTIVE:This study aimed to evaluate the RMS of patients with acute stroke compared with predicted values and to relate this to anthropometric variables, risk factors, and neurologic severity. METHODS:This is a cross-sectional study in the acute phase of stroke. After admission, RMS was evaluated by maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP); anthropometric data were collected; and neurologic severity was evaluated by the National Institutes of Health Stroke Scale. The analysis of MIP and MEP with predicted values was performed by chi-square test, and the relationship between anthropometric variables, risk factors, and neurologic severity was determined through multiple linear regression followed by residue analysis by the Shapiro-Wilk test; P < .05 was considered statistically significant. RESULTS:In the 32 patients studied, MIP and MEP were reduced when compared with the predicted values. MIP declined significantly by 4.39 points for each 1 kg/m2 increase in body mass index (BMI), and MEP declined significantly by an average of 3.89 points for each 1 kg/m2 increase in BMI. There was no statistically significant relationship between MIP or MEP and risk factors, and between MIP or MIP and neurologic severity in acute phase of stroke. CONCLUSION:There is a reduction of RMS in the acute phase of stroke, and RMS was lower in individuals with increased age and BMI.