The effects of different irrigation and crop level regimes on grapevine cv. Tempranillo performance in a Mediterranean climate were studied under field conditions over a four year period (2005–2008). Vines were subjected to three irrigated treatments providing 100%, 50% and 25% of crop evapotranspiration (ETc) plus a dry-farmed regime. In addition, two crop levels (high and low) established by veraison cluster thinning were studied for each of the treatments described. Increased irrigation doses resulted in higher yield and vine growth, although the 25% ETc treatment showed the highest irrigation water use efficiency with yields similar to the 50% ETc treatment. The short and long-term (following crop season) effects of the imposed treatments on some vegetative and productive parameters (i.e. the leaf area index and cluster weight) were related to vine water status, particularly when considering the pre-veraison period. Irrigation increased must titratable acidity (TA) but did not affect total soluble solids or pH. Cluster thinning resulted in a higher leaf area:yield ratio and lower yield even though a compensatory increment in cluster weight was observed at the low crop level treatments. For similar Brix, cluster thinning decreased TA and increased must pH, a negative feature since in the studied area must pH values are generally too high. Irrigation at 25% of ETc can be considered like a very worthwhile strategy for increasing yield against a dry-farmed vine, while at the same time maximizing water use efficiency without compromising grape composition.