We conducted a study to assess the factors that affect language development in infants and toddlers using data obtained during developmental screening. Our study group consisted of 505 children-244 (48.3%) boys and 261 (51.7%) girls, aged 5 to 27 months. The children were divided into four age groups: group 1, which we designated as the “6 months” group (age range: 5 to 7 mo); group 2, designated as the “12 months” group (11 to 13 mo); group 3, designated as the “18 months” group (17 to 19 mo); and group 4, designated as the “24 months” group (23 to 27 mo). In addition to demographic data, we compiled data using the Denver II Developmental Screening Test, as well as neurologic examination findings and medical histories. At 6 months, the social item “Works for toy out of reach” was positively related to all language development items. Two gross motor development items-“Pull to sit, no head lag” and “Lifts chest with arm support”-were related to the “Turns to sound” and “Turns to voice” items, respectively. Overall, children whose mothers had higher education levels and who were living in higher socioeconomic areas showed significantly greater language development, as did boys, specifically. At 12 months, higher maternal ages, some gross motor development items, and some social items were related to better language development, and children living in higher socioeconomic areas had a significantly increased ability to pass the “4 words other than mama/dada” item. At 18 months, the ability of girls to pass the “4 words other than mama/dada” item increased, and children who passed the “4 words other than mama/dada” item did not pass the “Throws ball” gross motor item. At 24 months, children whose mothers were older had better “Combines 2 words” and “Speech half intelligible” items, girls had better “Comprehends prepositions (such as under/above)” skills, and boys had better “Shows 4 parts of doll” skills. We conclude that language items appear to change together with gross motor items and social development, and that they can be influenced by a family's socioeconomic level. However, as children get older, language development diverges from gross motor development.