The aim of present investigation was to study the changes in weight and external measurements and the rates of growth of the internal organs and to compare these findings in infants who died of the sudden infant death syndrome (SIDS). The subjects were 165 infants (100 males and 65 females) who died in Leningrad in 1983-1989 in the first five months of life. Relative growth rates for each month were calculated for weight, external measurements and organ growth, and their ratio was also calculated. Apparent discordance in growth rates was revealed when contrasting the rates for weight, length, head and chest circumference to the growth rates of internal organs and when compared them with each other. The present data show the relation of specific growth patterns to SIDS.