The effect of sample size on the compressive strength of bulk metallic glass with nominal composition of (Zr55Cu30Al10Ni5)99Nb1 has been investigated. Ultrahigh strength ductile bulk metallic glass has been achieved in small dimensions. The variability of compressive strength is also analysed with the aim of weibull statistics. The weibull moduli of 25.5, 17.34 and 4.6 have been calculated for samples with 1, 3 and 5 mm in diameters, respectively. The results showed that the weibull moduli is strongly size dependent. The smaller sample exhibited more uniformity of compressive strength and more reliable in practical application as well.