The ECHAM-OPYC3 GCM is used in conjunction with previous results from analyses of the impact of atmospheric circulation at 925 and 500 hPa levels on the distribution of daily precipitation for Mediterranean Spain (Romero et al, 1999a, 1999b) to give estimates of the probable annual precipitation for the late 21st century. The down-scaling technique used involves the matching of daily circulation output from the model for two ‘present’ (1971-80 and 1981-90) and two ‘future’ (2080-89 and 2090-99) decades with analogue days occurring during the 1984-93 decade using ECMWF data. The matched days are then included in one of the 19 circulation types identified by Romero et al (1999b) if significant rainfall was produced. The indicated future frequency of each circulation type is compensated with reference to the contemporary difference between model and real frequency, so that the analysis also provides a verification of the performance of the ECHAM GCM. In general the agreement is very good, though for this southerly region the model appears slightly to under-estimate the frequency of easterly type circulations, many of which yield some of the most significant autumn severe storm rainfalls along the Mediterranean coast, and over-estimate the frequency of westerly type situations. An estimate of the future annual precipitation distribution is then derived using previously established relationships between circulation type and daily precipitation distribution. Results suggest that significant annual precipitation reduction to -12% will occur for Andalucía and the upland parts of Cataluña, largely because of a reduction in winter rainfalls. In contrast an increase in annual totals to +16% is indicated along the coast between Almería and the French border, mostly due to increasing severe storm activity during the late summer and autumn months. Key words: Climate change; Rainfall; Mediterranean; Down-scaling; GCMs