This study aimed to estimate social contact patterns directly by asking participants to record their physical and nonphysical contacts over a single day in eight European countries. The researchers collected data from 7,290 participants, who reported an average of 13.4 contacts per day. The findings revealed significant diversity in contact types, durations, and frequencies, challenging the notion that contact rates alone capture transmission dynamics. Children had more contacts than adults, and those living in larger households had more contacts. More intense contacts, such as those lasting longer or occurring more frequently, tended to be physical. Mixing patterns were similar across countries, with individuals tending to mix assortatively by age, especially schoolchildren and young adults. A preliminary model indicated that 5- to 19-year-olds would experience the highest incidence during the initial phase of an emerging infection transmitted through social contacts. This study provides valuable insights into contact patterns relevant to respiratory and close-contact infectious diseases, enhancing the parameterization of mathematical models used to design control strategies.This study aimed to estimate social contact patterns directly by asking participants to record their physical and nonphysical contacts over a single day in eight European countries. The researchers collected data from 7,290 participants, who reported an average of 13.4 contacts per day. The findings revealed significant diversity in contact types, durations, and frequencies, challenging the notion that contact rates alone capture transmission dynamics. Children had more contacts than adults, and those living in larger households had more contacts. More intense contacts, such as those lasting longer or occurring more frequently, tended to be physical. Mixing patterns were similar across countries, with individuals tending to mix assortatively by age, especially schoolchildren and young adults. A preliminary model indicated that 5- to 19-year-olds would experience the highest incidence during the initial phase of an emerging infection transmitted through social contacts. This study provides valuable insights into contact patterns relevant to respiratory and close-contact infectious diseases, enhancing the parameterization of mathematical models used to design control strategies.