A Syrian Lentil variety was grown at ambient and elevated CO₂ (750 µmol mol^-1)and at varying levels of Nitrogen fertilisation. Elevated CO₂ led to an increase in plant dry matter, pod number and seed yield at all Nitrogen levels. The seed yield response plateaued at about 50 kgha^-1 under ambient CO₂ but continued to respond up to 100 kgha^-1 under elevated CO₂. The margin of response to elevated CO₂ was up to x2. The number of active root nodules was influenced by both elevated CO₂ and Nitrogen nutrition. A small but significant response (10% increase) to elevated CO₂ was recorded. The highest (100 kgha^-1) and the lowest (5 kgha^-1) Nitrogen levels suppressed both the early appearance of nodules and the maximum number produced. Intermediate levels of Nitrogen (25 - 75 kgha^-1)gave similar responses to each other. There was no strong correlation between nodule number and yield. Residual nutrition in the "soil" (perlite) at the end of the experiment was low indicating high plant uptake. Uptake under elevated CO₂ was slightly higher than under ambient CO₂.