OBJECTIVE Our purpose was to evaluate the dental arch relationships using the GOSLON Yardstick in children with cleft lip and or cleft palate in Northern Finland. METHODS The subjects consisted of 62 Finnish patients (36 girls and 26 boys) with clefts born between 1995-2005 in the Northern Ostrobothnia Hospital District of Finland. There were 36 patients with cleft palate, 9 with unilateral cleft lip and palate, 6 with cleft in soft palate, 5 with bilateral cleft lip and palate, 2 with cleft lip and 4 with submucous clefts. The study casts were obtained at the mean age of 6.3 years (5.8-7.8 years) and the cases were selected randomly. The dental arch relationships were assessed by the GOSLON Yardstick method by one calibrated researcher. RESULTS After the assessment, 77.1% of cases were allocated to categories 1 and 2 (excellent and good), 10.4% category 3 (fair), and 12.5% categories 4 and 5 (poor and very poor). Patients with cleft palate had good prognosis in 84.6% of the cases. Of the patients with soft palate clefts and unilateral cleft lip and palate, 66.7% were allocated to categories 1 and 2. Bilateral cleft lip and palate patients had the poorest prognosis. Patients with submucous cleft and cleft lip had all good prognosis. CONCLUSIONS The GOSLON Yardstick is a useful method for assessing dental arch relationships and treatment prognosis not only in cleft lip and palate patients, but also in cleft palate patients.