BackgroundGlobally, two out of five children living with HIV (CLHIV) are unaware of their HIV status, and a little more than 50% are receiving antiretroviral therapy (ART). This paper describes case-finding strategies and their contribution to identifying CLHIV and linking them to ART in Nigeria.MethodsThis before-after study used program data abstracted during the implementation of different paediatric-focused strategies (provider-initiated testing and counselling, orphans and vulnerable children testing, family-based index testing, early infant diagnosis (EID), community-driven EID, and community-based testing) delivered in health facilities and in communities to improve HIV case identification. Data were abstracted for children (0 to 14 years) who received HIV testing services and were initiated on ART in Akwa Ibom State, Nigeria during the pre-implementation period (April–June 2021) and during the implementation period (July–September 2021). Descriptive statistics were used to describe the testing coverage, positivity rate (proportion of tests that were positive for HIV), linkage to ART, and ART coverage, by age, sex, and testing modality. Interrupted time series analysis (ITSA) on STATA 14 was used to estimate the effect of the implementation of these strategies on HIV testing uptake and positivity rate at a 0.05 significance level.ResultsA total of 70,210 children were tested for HIV within the six-month period, and 1,012 CLHIV were identified. A total of 78% (n = 54,821) of the tests and 83.4% (n = 844) CLHIV were diagnosed during the implementation period. During implementation, the HIV positivity rate increased from 1.09% (168/15,389) to 1.54% (844/54,821), while linkage to ART increased from 99.4% (167/168) to 99.8% (842/844). The contribution from community-based modalities to CLHIV identified increased from 63% (106/168) to 84% (709/844) during the implementation, with the majority, 60.8% (431/709), from community-based index testing. Overall, ART coverage increased from 39.7 to 55.6% at the end of the intervention period.ConclusionThe findings show that expanding differentiated HIV testing approaches provided mostly in the community significantly increased pediatric case identification. However, ART coverage remains low, especially for younger age groups, and requires further efforts.