New protocols based on ALK-targeted therapy by crizotinib or other ALK targeting molecules have opened for the treatment of patients with neuroblastoma (NB) if their tumors showed mutation and/or amplification of the ALK gene. However, tumor samples are not always available for analysis of ALK mutational status in particular at relapse. Here, we evaluated the ALK mutational status of NB by analysis of circulating DNA, using the droplet digital PCR (ddPCR) system. ddPCR assays were developed for the detection of ALK mutations at F1174 and R1275 hotspots found in NB tumors and was applied for the analysis of circulating DNA obtained from 200µl of serum or plasma samples collected from 114 patients. The majority of samples were obtained from patients with high risk NB (stage 4 (n=97), stage 2/3 with MYCN amplification (n=7) and stage 3 without MYCN amplification (n=10)). ALK mutations were found in circulating DNA of 24 cases (22%). The mutations F1174L (exon23 position 3520, T>C and position 3522, C>A) and the mutation R1275Q (exon 25 position 3824, G>A) were detected in circulating DNA of 2, 11 and 15 patients respectively. Concurrent distinct mutations were observed in 4 cases, indicating tumour heterogeneity. A perfect concordance for the mutation F1174L (position 3520, T>C) was observed when we compared the circulating DNA and tumor DNA samples. For the mutations F1174L (position 3522, C>A) and R1275Q (position 3824, G>A), our test showed a good sensitivity (85% and 92%, respectively) and a high specificity (91% and 98%, respectively). In conclusion, these ddPCR assays offer reliable, noninvasive blood tests to assess ALK mutational status at F1174 and R1275 hotspots and should help clinicians to identify patients showing an ALK mutation in particular when no tumor tissue is available. Moreover, the analysis of ALK mutation in circulating DNA may help to capture tumor heterogeneity.