Afield experiment was conducted to assess the growth and yield of watermelon Citrullus lanatus [(Thunb.) Matsum. & Nakai] under acidic soil conditions in Calabar, Cross River State, Nigeria. The experiment was a 3 × 3 factorial experiment laid in a randomized complete block design (RCBD) with three replications. The factors studied were varieties (Heracles F₁, Kaolack and Sugar Baby), lime rates (0 t ha^-1, 2.7 t ha^-1 and 5.7 t ha^-1), and their interactions on watermelon growth and yield traits. Heracles F₁ and Kaolack outperformed Sugar Baby (p ≤ 0.05) regarding growth and yield traits. Lime rates of 2.7 t ha^-1 and 5.7 t ha^-1 increased the initial soil pH range (4.6–4.9) by 21.74% (5.4–5.8) and 43.48% (6.4–6.7), respectively. These rates improved the soil pH to a range suitable for watermelon cultivation in the study area. Vine length, number of leaves, transverse and longitudinal sections of the fruits and sugar content of the fruits had ≥ 50% heritability, a useful index in the selection of choice growth and yield traits in watermelon. Overall, GAM was greater than GA for each of the traits except for the total number of seeds per fruit. Multi-location studies are recommended to give further insights to this pilot study.