OBJECTIVE To use the maximum loudest phonation time (MLPT) on evaluation of unilateral vocal fold paralysis. METHODS The MLPT, maximum comfortable phonation time (MCPT) and maximum phonation time (MPT) were tested and collected in 17 patients with unilateral vocal fold paralysis. The data of ratio value of MLPT to MCPT also was collected. The stroboscopy, perceptual measures and self-questionnaire also were used in evaluation of vocal fold and voice in all patients. Correlation coefficients were used as measures of agreement. RESULTS MLPT was (5.0 +/- 4.0)s, MCPT was (5.4 +/- 4.1)s, and MPT was (6.1 +/- 4.5)s in patients. The MPT was composed of MLPT in 4 patients and MCPT in 13 patients. The MLPT/MCPTa was 1.08 +/- 0.47. MLPT was positively correlated with MCPT and MPT, respectively (r = 0.679, P < 0.01; r = 0.878, P < 0.01), and MCPT also was positively correlated with MPT (r = 0.993, P < 0.01). MLPT, MCPT and MPT was negatively correlated with G value which was from GRBAS scale, respectively (r = -0.620, P < 0.05; r = -0.564, P < 0.05; r = -0.665, P < 0.05). The MLPT/MCPTa was positively correlated with the value of question 4 from self-questionnaire (r = 0.534, P < 0.05). MLPT, MCPT or MPT had no correlation with self-questionnaire, GRBAS perceptual evaluation or stroboscopy measures significantly. CONCLUSIONS MLPT, MCPT or MPT can be used for evaluation of aerodynamic measures in unilateral vocal fold paralysis. The MLPT may be easiest to operate in clinic. The MLPT/MCPTa ratio can assess dysphagia in unilateral vocal fold paralysis patients.