© 2021, Turkish National Pediatric Society. All rights reserved.Background. To date, studies have mostly focused on the language outcome of early-auditory interventions including amplification for congenital hearing loss within the first 6 months. We aimed to examine the effect of early-auditory intervention in patients with congenital hearing loss on cognitive, motor and language outcomes, and determine the clinical variables that affect developmental outcomes. Methods. The medical records of 104 patients were retrospectively reviewed. Children were evaluated by the Bayley Scales of Infant and Toddler Development, Third Edition. Results. The median ages of confirmation of hearing loss, amplification, starting auditory-verbal intervention and cochlear implantation were 9, 10, 13 and 19 months, respectively. Of the patients, 26% received a hearing-aid fitting ≤6 months of age. Fifty-one children (49%) had additional disabilities. The median cognitive, language and motor scores of children with no additional disabilities were 95 (65-115), 68 (47-103) and 97 (58-130), respectively and children with early-auditory intervention (≤6 months) demonstrated higher cognitive, receptive and expressive language subscale scores than late-auditory intervention group (p<0.05) whereas there was no significant difference in motor scores (p>0.05). A significant negative correlation was found between additional disability and cognitive, language and motor outcomes (r=-0.78, r=-0.54 and r=-0.75, respectively p<0.01). There was a significant negative correlation between language outcomes and the degree of hearing loss (r=-0.20, p<0.05). Multiple regression analyses revealed that additional disability and early-auditory intervention showed a significant amount of variance in cognitive and language scores. The early intervention did not make a significant, independent contribution on motor outcomes whereas additional disability did. Conclusions. Presence of additional disability was the strongest significant variable on developmental outcomes in hearing-impaired children. In children with no additional disability, significantly better cognitive and language scores were associated with the early-auditory intervention. Motor skills were not affected by the early-auditory intervention.