<p>Cochlear implants are known to afford speech perception in quiet and noise, especially for adult recipients with post-lingual hearing loss. Several factors influence speech perception outcomes in adults with post-lingual hearing loss; duration of deafness prior to implantation being an important one. The aim of the present study was to compare word recognition scores (WRS) in quiet and in four-speaker babble noise among adult unilateral cochlear implant users with different durations of deafness prior to implantation. Two word lists from the Conventional Speech Identification Test in Marathi were administered in quiet and in four-speaker babble noise created using recordings of two male and two female speakers. Lists were administered in quiet and at + 15 dB SNR, with stimulus presentation level maintained at 60 dB HL. Participants were 25 adult cochlear implant users, divided into two groups according to duration of deafness prior to implantation (0–3 years and ≥ 5 years). Scores were compared using an independent samples t-test. Participants with duration of deafness of 0–3 years had significantly higher WRS in quiet (54.67 ± 15.69%) than those with duration of deafness ≥ 5 years (40.80 ± 12.62%; t = 2.33, <i>p</i> &lt; 0.05). Likewise, WRS in noise was significantly higher, showing greater difference in the short-duration group compared to the longer-duration group (48.00 ± 14.42 vs. 35.20 ± 12.76%; t = 2.33, <i>p</i> &lt; 0.05). In both groups, WRS in quiet exceeded that obtained in noise. Duration of deafness has a significant impact on word recognition outcomes in adult cochlear implant users. Individuals implanted after shorter durations of deafness demonstrate better speech recognition performance in both quiet and noisy listening conditions. These findings support early cochlear implantation and may assist clinicians during preoperative counselling and expectation management.</p>