The intensive completion of lambs in high pens with a grid floor allows the animals to stay in a healthy environment, with less parasitic load, protection of predators, reduction in energy costs and a better microclimate, however little is known about the productive behaviour of lambs under this production system. The identification of factors that influence the productive behaviour of lambs in this type of housing is crucial to improve their productivity. The objective of this study was to determine the effects of the farm, year and time of the year on some productive variables of lambs completed in high pens with a grid floor in Mexico’s sub-humid tropic. 882 data were analysed for daily post-weaning weight gain (GDP), final body weight (GMP) and completion period (DE) for male lambs from four farms (farm A, n = 166; farm B, n = 122; farm C, n = 350; farm D, n = 244). The statistical model includes the fixed effects of the farm (A, B, C and D), the time of the year (rain and dry) and the year (2010, 2011, 2012 and 2013) on GDP, PCF and DE. The model included initial body weight as covariable. The overall averages for GDP, CPP and DE were 263 g, 35 kg and 77 days respectively. The farm affected (P < 0.001) all the variables assessed. The time of the year affected (P < 0.001) CPT and DE, but not GDP. The year affected (P < 0.001) all the variables assessed. Interaction between farms × time of year affected (P < 0.001) BCP and DE, but not GDP. In conclusion, the production behaviour of lambs finished in high cages in the sub-humid tropics in Mexico was affected by the farm, the year and partly by the time of the year and the interaction between farms × time of year.