Dy3Co, in addition to two antiferromagnetic (AFM) transitions (35 K and TN∼ 44 K), exhibits a Griffiths-like phase around 65 K and it persists up to ∼1 GPa pressure. External pressure alters the magnetic state significantly and results in increase (decrease) of TN (TAF) by 6.5% (∼13%) with dTN/dP ∼ 3 K/GPa (dTAF/dP ∼ −4.5 K/GPa). Increase in metamagnetic critical field and other changes with pressure indicate the strengthening of AFM interactions in Dy3Co. On the other hand, Dy3Ni shows three magnetic transitions at To∼ 55 K, T1∼ 39 K (AFM) and T2∼ 24 K (AFM). Experimental evidence points to the magnetic ordering temperature to be at To∼55 K instead of 39 K as claimed by certain reports. External pressure reduces (increases) the transition temperature To (T1) by ∼7.9% (7.6%) at a rate of −3.5 K/GPa (2.5 K/GPa). Pressure has only marginal effect on the other low temperature transition at T2. Additionally, ac-susceptibility data exhibit spin-glass like features, which seem to arise from domain wall movements and probably random freezing of small components of spins, coexisting with dominant long-ranged non-collinear AFM structure in these compounds.