Two experiments were carried out to study groundnut (Arachis hypogaeaL.) response to thinning time and intensity after anthesis at Redland Bay Farm, Southeast Queensland, Australia, during 1987/88 (Experiment 1) and 1989/90 (Experiment 2). Six cultivars were included in Experiment 1: Improved Virginia Bunch (IVB), NC7, Q18801 (Virginia type), TMV-2, McCubbin and Red Spanish (Spanish type); and two cultivars in Experiment 2: IVB and Red Spanish. These were thinned to 0 (control) or 50% at 42 or 91 days after planting (DAP) in Experiment 1; and 0 (control), 33, 50, 66 or 75% at 42 DAP in Experiment 2. Treatments were laid out in a randomized complete block design (RCBD) with three replications in both seasons. A 50% thinning at 42 DAP reduced intercepted photosynthetically active radiation but fadiation use efficiency, crop growth rate and total dry mass increased in all cultivars by maturity. A 50% thinning at 91 DAP significantly reduced groundnut production. Also, a thinning intensity of >66% reduced groundnut production. Thus, 50% plant removal during early reproductive growth may not significantly reduce groundnut production. This implies that an early control of insect pests (e.g. termites) could result in yield compensation amongst the remaining plants such that yield losses would be minimal by maturity of the crop.