Multiple studies have demonstrated an association between cancer and nonsyndromic oral clefts in different populations. In this study, we assessed the occurrence of nonsyndromic oral clefts in families of patients with acute lymphoblastic leukemia (ALL, = 50) and controls ( = 125). The parents of the patients answered a questionnaire with basic demographic information and family history of nonsyndromic oral clefts in first-degree relatives. Statistical analysis was carried out using Fisher's exact test. In the ALL group, 22 (44%) were male and 28 (56%) were female, and the average age was 13.2 ± 12.2 years. In the control group, 64 (51.2%) were male and 65 were female and the average age was 11.3 ± 10.3 years. Two out of 50 patients (4%) with acute lymphoblastic leukemia had a positive history of nonsyndromic oral clefts, whereas there were no reported occurrences of nonsyndromic oral clefts in the control group (OR: 12.94, 95% CI: 0.61-274.6, = 0.08). Despite the limited population, the frequency of nonsyndromic oral clefts was increased in the first-degree relatives of patients with acute lymphoblastic leukemia. Studies with larger samples and molecular analyses are needed to better understand the possible etiological relationship between cancer and nonsyndromic oral clefts.