The efficacy of the probiotic feed product, Calsporin® (Bacillus subtilis C-3102) in weaned piglets was evaluated by statistical analysis of the combined results from four different experiments. The body weight, average daily gain, feed intake, feed conversion ratio and mortality data from these four experiments were tested for homogeneity before being pooled and analysed as a whole, with experiment being included as a blocking factor. Piglets fed diets supplemented with Calsporin® were significantly heavier (3.4%) at 43 days (P < 0.05), their feed intakes decreased by 2.1% and feed efficiency (FCR) improved by 3.2% between 15 and 43 days, although these latter differences were not significant. Over the entire study period (day 1 to 43), significant improvements in daily gain (4.8%) and feed efficiency (6.2%) were observed with Calsporin® supplementation (P < 0.05). The results demonstrated that Calsporin® at 30 mg/kg inclusion in commercial-type diets can improve zootechnical performance in weaned piglets.