Two cases of neonatal renal tubular dysfunction and metabolic acidosis due to maternal sniffing of a product containing toluene are reported. Both mothers had been sniffing regularly throughout their pregnancies. The infants were dysmature and had some dysmorphic features. They had hyperchloraemic acidosis and exhibited amino-aciduria. The metabolic changes were however transient. It is suggested that the sniffing of toluene containing solvents during pregnancy may change membrane permeability in both the proximal as well as distal renal tubules and may also enhance liver enzyme activity in the foetus.