Summary Gremmeniella abietina isolated from Pinus halepensis in Spain was characterized based on disease symptoms and conidia morphology. The disease symptoms, which became more evident in the spring, included drying up of needles and branches with some distortion of terminal twigs, resulting in dieback and sometimes to death of trees of all sizes. Variation in conidia size and growth rate was investigated between 15 isolates from Spain, and the conidia morphology was compared with four isolates from Finland, four from Switzerland and three from the US. Great variation occurred between Spanish isolates both in growth rates and in conidia size. The growth rates of the isolates were greatest on malt agar amended with pine needle extract and at 15°C. The length and the width of the conidia of the isolates from Spain ranged between 10.7–44.8 and 1.5–4.4 μm, and most of them had three septa. The results suggest that the isolates from Spain do not belong to the Alpine biotype, and the disease symptoms caused by these isolates resembled those of the European biotype.