Abstract The activity and selectivity for propene oligomerization of pure synthetic mica-montmorillonite, SMM, as well as SMM incorporating various transition metals, was studied. The effect of incorporating nickel into the matrix as well as ion-exchanging (IX) nickel, zinc and cobalt into the interlayer spaces was investigated. Matrix nickel removed the long induction period characteristic of SMM and ion-exchanged SMM. Reducing the ion-exchanged nickel removed the induction period in the oligomerization reaction. Removal of the reduced nickel by carbon monoxide leaching caused an increase in activity. Water drastically decreased the catalyst lifetime. Zn (IX) SMM had a greater activity than Ni (IX) SMM, and Co (IX) SMM was initially more active than either but deactivated rapidly. Oligomerization selectivity was fairly constant throughout this study and the products were predominantly trimers and tetramers. The carbonaceous deposit formed during deactivation consisted mainly of high boiling point hydrocarbons but the presence of nickel increased the amount of “graphitic” carbon formed. Deactivation of the catalyst was mainly due to the presence of the latter deposits.