Purpose: This study evaluated the efficacy of a 4-week straw phonation in water (SPW) exercise program on aging-related vocal fold atrophy (VFA), with a secondary objective to examine the immediate effects of SPW exercises. Method: Thirty-eight older adults aged 60 years and above formally diagnosed with aging-related VFA were randomly assigned into an experimental group undergoing SPW exercises with an 8-cm depth of straw submersion into water for 4 weeks plus vocal hygiene practice (n = 20), and a control group with only vocal hygiene practice (n = 18). Outcome measures included laryngeal endoscopic measures of glottal gap, auditory-perceptual ratings of voice quality, acoustic measures, aerodynamic measures, and standardized self-assessment questionnaire scores. An additional round of acoustic and aerodynamic assessment following 20 min of SPW exercises was conducted to examine the immediate effects. Results: Significant improvements in normalized glottal gap area, perceptual rating of breathiness, smoothed cepstral peak prominence, harmonics-to-noise ratio (HNR), mean oral airflow, subglottal pressure and laryngeal airway resistance at comfortable loudness, Voice-related Quality of Life scores, and Chinese Vocal Fatigue Index Factor 3 scores were observed in the experimental group relative to the control group. There were also significant immediate effects for HNR, mean oral airflow, subglottal pressure, and laryngeal airway resistance. Conclusions: These findings suggested significant immediate improvements in vocal function following SPW exercises, with additional significant improvements in vocal function as well as significant improvements in quality of life following the 4-week SPW exercise program. Further studies with more long-term followup are recommended to better understand the efficacy of SPW exercises with deep levels of straw submersion into water as an effective clinical option for the management of hypofunctional dysphonia associated with aging-related VFA.