The study explores the former Union of Soviet Socialist Republics (USSR) countries’ under‐fives child mortality rates (CMR) and child abuse‐related deaths (CARD) since the end of the Soviet Union, and asks whether there has been an ‘under‐reporting’ of CARD? World Health Organization under‐fives mortality rates per million (pm) were extracted for 1988–90 and compared with 2008–10 for CMR and confirmed and possible CARD. Possible CARD are undetermined deaths (UnD) and ill‐defined signs and symptoms (IDSS) deaths as these categories have been linked to under‐reporting of CARD. CMR and CARD odds ratios were calculated and correlated to determine the possible under‐reporting of CARD. Seven countries met the United Nations International Children's Education Fund (UNICEF) objective of reducing CMR; five halving their previous USSR rate. The Russian CARD rate at 29 pm is the highest, but six countries’ rates were less than ten pm. UnD increased in Kazakhstan 13‐fold, Belarus eight times, Ukraine seven times and Russia more than four times. IDSS deaths trebled in Belarus, and rose more than 25 per cent in Kazakhstan, Georgia and Ukraine. CARD significantly correlated with UnD but not with CMR. Odds ratios of CMR to all three CARD categories were substantial, more than 4.1:1 in Belarus, Kazakhstan, Russia and Ukraine, indicating possible under‐reporting of CARD. Despite CMR improvements, this first‐ever study of the former USSR countries should alert the authorities of Belarus, Kazakhstan, the Russian Federation and Ukraine to the extent of possible child abuse. Copyright © 2014 John Wiley & Sons, Ltd. ‘Seven countries met the UNICEF objective of reducing CMR Key Practitioner Messages: This first‐ever study of child mortality and child abuse deaths in the former USSR found improvements in child mortality but unrecognised child protection issues. Child homicides ostensibly fell in every country but Russia. Major rises in undetermined and ill‐defined deaths in Belarus, Kazakhstan, Russia and Ukraine are indicative of under‐reporting but did not occur in the other former USSR countries. There is an urgent need to focus upon violence against children as either child abuse is not recognised, or it is being deliberately ignored. ‘Either child abuse is not recognised, or it is being deliberately ignored’