•The mean amount of screen time in infants aged 2–11 months was 6−17 min a day.•Technoference in mother-infant interactions happened, on average, 5–6 times a day.•Maternal educational level was negatively related to infant screen time. This study aimed to examine longitudinal developmental patterns in the daily amounts of screen time and technoference in infants aged 2, 4, 7, and 11 months and to examine associations with maternal sociodemographic factors across all age groups. The results showed that the amount of screen time varied between 6 and 17 min a day, while interruptions in mother-infant interactions due to maternal use of digital technology occurred between 5 and 6 times a day. There was a significant increase in infant screen time from 2 to 4 months, from 4–7 months, and from 7–11 months, and in technoference from 2 to 4 months and from 4–7 months. Maternal age and household income were not associated with infant screen time, but maternal educational level was negatively associated with infant screen time throughout the first year. No associations were found between technoference and maternal age, maternal educational level, or household income. Future research focusing on infant screen time and technoference should aim at including samples that reflect the general population, include measures of screen time and technoference that do not rely on parental report, and include measures of the effects of early infant screen time and technoference on later development.