Physical tests including water absorption, wettability tests, etc on leathers produced from delimed pelt and formaldehyde pretanned pelt using sulphochlorinated oil (Immergan) indicate that a pretanning with formaldehyde gives higher water absoprtion and less sink time of the finished leathers when compared with straight Immergan tanning. For practical tanning purposes 15per thousand Immergan seems to be the optimum concentration for retanning the formaldehyde tanned leathers. When these leathers are dyed with various kinds of dyestuffs and tested for fastness properties such as light, solvent and washing, using grey scales, the following results are obtained: (a) sulphonyl chloride tanned leathers can be dyed with acid, premetallised and reactive dyes with good penetration and uniform dyeing. Reactive dye shows good fastness towards light, solvent and washing. (b) when dyeing Immergan tanned leathers with reactive dye, chrome mordanting is found to be unnecessary (c) sulphonyl chloride tanned leather is found to possess very good brilliancy and depth of shade when dyed with all the dyes, used in this investigation.