Variability of grain weight spike-1 was studied in 10 wheat genotypes: 'Ana Morava', 'Julija Mono', 'Gruža', 'Kuna', 'Lasta', 'Balkan', 'Rodna', 'NS Rana 2', 'Partizanka', 'Pobeda', grown over three experimental years under different environmental factors. The experiment was set up as a randomized block design in three replications. Differences in the average values of grain weight spike-1 among tested cultivars were determined in all three years. On average, for all genotypes, grain weight spike-1 was highest (2.32g) in the first experimental year (2005/06), and lowest (1.95g) in the second year (2006/07). For all investigated wheat cultivars, in the third experimental year, the average value of grain weight spike-1 was 2.24g, while the total average value for all cultivars and three experimental years was 2.17g. 'Ana Morava' had the highest average values for grain weight spike-1 in all three experimental years, while the lowest grain weight spike-1 was obtained in 'Balkan' (1.81g) in the second year 'Lasta' (1.40g) and in the third experimental year 'Partizanka' ( 1.91 g). On average, 'Ana Morava' had the highest value (2.67g) of grain weight spike-1, while the lowest average value (1.94g) was recorded in 'Balkan'.