The expression of neuropeptide Y (NPY) and NPY-Y1 receptor (NPY-Y1R) in relation to that of tyrosine kinase A (trkA), nerve-growth-factor low-affinity-receptor (LNGFR) and the transcription factor N-myc was studied in 26 neuroblastomas and one ganglioneuroma by quantitative Northern-blot analysis. A correlation of NPY-Y1R with LNGFR (r = 0.85, p < 0.01) and trkA (r = 0.38, p < 0.05), respectively, could be shown, while no correlation between NPY and its receptor NPY-Y1R was observed. Comparison of a high and a low level NPY expressing group revealed that the high NPY expressing group also had high LNGFR and high trkA levels while the low NPY expressing group had low LNGFR and low trkA levels which were significantly different (NPY: p = 0.035, trkA: p = 0.008, LNGFR p = 0.004). Dividing the tumors in a high and a low N-myc expressing group showed that the low N-myc expressing group contained both high and low trkA expressing tumors while the high N-myc expressing group exclusively were low level trkA expressing tumors. The frequency distribution in both groups concerning trkA expression showed a significant difference (p < 0.01). In conclusion the coexpression of NPY-Y1R and LNGFR or trkA may indicate a similar gene regulation during ontogenesis of the peripheral nervous system.