Background & Aims: Mucosal healing (MH) has become an important therapeutic goal in Crohn’s disease (CD). Repeated assessment by ileocolonoscopy is less feasible, especially in children. The Pediatric Crohn’s Disease Activity Index ( PCDAI) does not correlate well with mucosal inflammation. We aimed to develop and validate a multi-item index, based on clinical and laboratory parameters, which could reflect MH in clinical trials as well as for clinical practice. Method: We utilized data from the prospective ImageKids study where children with CD underwent ileocolonoscopy concurrent with recording of explicit clinical and laboratory data, at disease onset or thereafter. We conducted linear regression analysis to identify PCDAI items and lab tests that are associated with the Simple Endoscopic Score for CD (SES-CD). We employed a combined clinimetric judgmental approach to augment a statistically derived index of inflammation associated with the SES-CD. We validated the index on an independent prospective cohort from Korea of children whose workup included ileocolonoscopy, clinical and laboratory data. Results: The derivation and validation cohorts included 154 and 86 children, respectively (n=240; age 14.6±2.6 years; SESCD 7.8±8.2), of whom 24 (16%) and 56 (65%) had MH (defined as SES-CD3), respectively. The stooling items of the PCDAI and fecal calprotectin were strongly and robustly associated with SES-CD in multivariate regression analysis (p0.05). Judgmentally, we included ESR and CRP, to form a weighted categorized MINI index. Using the MINI index with a cutoff of 8 for MH, the sensitivity, specificity, PPV and NPV over the validation cohort were, respectively, 91%, 68%, 84% and 80% (AUC=0.90, 95%CI=0.84-0.96). In the entire cohort (n=240) the correlation between MINI and SES-CD was r=0.784 (p0.001). Conclusions: In children with ileocolonic CD, the MINI-index can reflect MH with a good accuracy.