Agronomic and economic viability of rubber/cinnamon intercropping under 10 inter-row spacing systems of rubber ranging from 8.4m to 18.0m were tested. Spacing treatments with 8.4m-13.2m had single rows and those between 13.2m and 18.0m had paired rows of rubber. The total dry matter of harvested shoots, bark yield and the percentage dry matter in bark remained unaffected even at the third harvest in wider inter row spacing systems, viz: 12.0m and 13.2m single row and 14.4m-18.0m paired row systems. Pay back period for systems involving 10.8m, 12.0m. 13.2 single row and 15.6m, 16.8m and 18.0m paired rows was 5 years i.e., after three harvests of cinnamon compared to 11 years for sole crop rubber. Pay back in 5 years in systems involving 10.8m-13.2m single rows was the result of low expenditure on rubber due to its reduced density. In systems involving 15.6m-18.0m this was mainly due to the sustained higher yields from cinnamon. Though the reduced rubber densities incur considerable losses of income from rubber in the long run, the excess income obtained from cinnamon in the 5th year was almost sufficient to cover this loss and all the costs in the system involving 15.6m. In the 13.2m paired row system where the rubber density was higher than the standard, low pay back is due to both reduced income from cinnamon and greater expenditure on rubber. Suitability of rubber inter-row spacing involving 14.4m, 15.6m and 16.8m paired rows for viable rubber/cinnamon intercropping system is evident at this stage.