Although COC are at risk for long term adverse neurodevelopmental outcome, we found no difference in WPPSI-R Full Scale IQ scores in a cohort of COC and CON children of similar low SES tested at age 4 years. Both COC (79.0± 12.6) and CON (81.9±10.7), however, had Full Scale IQ scores markedly below the test mean of 100. We now report WPPSI-R IQ scores at age 6 years in a subset of this cohort. METHODS: Individuals masked to child group status administered the WPPSI-R at age 6 years. Because multiple factors may influence intelligence, the effect of home environment (Home Observation for Measurement of the Environment [HOME]), school experience(none, kindergarten, first grade), caregiver IQ, and continued caregiver drug use are also being assessed. RESULTS: To date 49 COC(median in utero exposure 99 days) and 43 CON of similar natal status, gender, and age at testing (73 mos.) have been tested. Groups do not differ (COC values presented first) in Performance IQ (84.8±15 vs 87.0±14.6, p=.48); Verbal IQ (82.5±12.3 vs 82.0±12.6, p=.84); or Full Scale IQ (81.8±13.8 vs 82.7±13.3, p=.76). So far caregiver Full Scale IQ in COC (n=19) and CON (n=13) do not differ(81.1±9.0 vs. 83.1±9.5, p=.56) whereas HOME scores (COC n=39; CON n=32) do (43.5 ± 5.9 vs 46.6±4.9, p=.010). Higher caregiver IQ score (p=.023), Total HOME score (p=.001), and school experience (p=.022) are associated with higher child Full Scale IQ score, whereas continued caregiver drug use (p=.004) is associated with lower IQ score. When Full Scale IQ scores of 44 COC and 41 CON tested at both 4 and 6 years were evaluated, there was no group (p=.75) or group by time (p=.44) difference; however, 27% COC and 39% CON children showed an increase in Full Scale IQ score over time(p=.001) (mean scores of COC 79.2±12.7 to 81.5±13.8 and CON 80.4±11.0 to 84.0±11.9). CONCLUSIONS: 1) Inner-city children do not differ in outcome on intelligence testing at age 6 years, regardless of in utero COC exposure; 2) In children tested at both 4 and 6 years IQ scores increased slightly in both COC and CON; this change is greeted with cautious optimism.