Abstract The main purpose of this paper is to find those values of the die radius r 0, pulling rate v and melt temperature T 0 at the meniscus basis which assures the growth of an Nd:YAG cylindrical bar with a prescribed diameter 2 r f for which the nonuniformities of the surface of the bar, due to small uncontrollable oscillations of v and T 0 are minimum possible. Numerical results are given for an Nd:YAG cylindrical bar of 5 mm diameter, grown in a furnace in which the vertical temperature gradient is k=33 K/mm. For a value of v in the range v∈ 0.0001,0.53 mm/s and a value of T 0 in the range T 0∈ 2244,3000 , four types of uncontrollable oscillations O i , i= 1,4 , of these parameters are considered: O 1= (Δ v=±0.001 mm/s and Δ T=±1 K), O 2 = (Δ v=±0.01 mm/s and Δ T=±10 K), O 3= (Δ v=±0.02 mm/s and Δ T=±20 K), O 4= (Δ v=±0.001 mm/s and Δ T=±30 K). For a set of six values of r 0 in the range r 0∈ 2.6,4.0 mm, the amplitude of the crystal radius variation due to the above four oscillations is computed. It is found that the amplitude of the crystal radius variation due to the considered oscillations is minimum for • r 0=2.6mm, v=0.0119mm/s, T 0=2305K for O 1; • r 0=2.6mm, v=0.0243mm/s, T 0=2303K for O 2; • r 0=2.6mm, v=0.0466mm/s, T 0=2299K for O 3; • r 0=2.7mm, v=0.0011mm/s, T 0=2360K for O 4.