Aggregate size and structure were investigated under turbulent conditions in stirred tank (ST) and Taylor-Couette-type (TC-type) devices. Root-mean-square radius of gyration, < Rg >, and zero-angle intensity of scattered light, I(0), were acquired as a function of stirring intensity, characterized by an experimentally obtained average hydrodynamic stress, (exp), determined by torque measurements. Evaluating aggregate images revealed that aggregate structure and shape are independent of the device type. However, in TC-type devices, the aggregates grow to three to four times larger sizes than inside ST, although the same and I(0) with (exp) is preserved for all investigated devices, with an exponent approximately equal to -0.5 and -0.7, respectively. (C) 2010 American Institute of Chemical Engineers AIChE J, 56: 2573-2587, 2010