In recent years a variety of glycoconjugates have been found associated with the plasma membrane of mammalian primary sensory neurones. The functional significance of these glycoconjugates remains obscure but their carbohydrate chains have been widely implicated in cell-cell recognition (or adhesion) during development. The plant lectin Bandeiraea simplicifolia I-B4 identifies a characteristic galactose-containing glycoconjugate associated with small diameter primary sensory neurones. In this study we have used a combination of lectin binding and retrograde tracing to examine the distribution of this glycoconjugate on sensory neurones which innervate different target tissues in the rat. The fluorescent tracer diamidino yellow was applied the cut end of peripheral nerves which selectively innervate either the skin, muscle or viscera. Retrogradely labelled neurones were then screened for lectin binding using a lectin-horseradish peroxidase conjugate. The results revealed that Bandeiraea simplicifolia I-B4 binding is associated with over one-third of neurones which innervate the skin, but only a small proportion of neurones innervating muscle or viscera.