A macroporous monolith comprising a polymer gel matrix was developed for application in continuous-flow catalytic reactions. Nanosized Pd(0) particles were loaded in a poly(N-isopropylacrylamide)-gel-based monolith by Pd(II) adsorption and subsequent reduction. The permeability of the Pd(0)-loaded monolith was compared with a commercial membrane filter with a pore size of several micrometers. The Pd(0)-loaded monolith exhibited excellent productivity in a continuous-flow Suzuki coupling reaction. Moreover, the Pd(0)-loaded monolith showed sustained performance over a 7-day period without Pd leaching.