Abstract Efficiency of somaclone production was examined using 10 processing tomato cultivars and 18 growth regulator treatments. Although zeatin has been reported to induce shoot development most readily, a combination of IAA (5.7 µmol·liter–1) and kinetin (4.7 µmol·liter–1) was found to be equal to zeatin in shoot regeneration efficiency and reduced the time required for shoot production. Rooting was achieved by transplanting the in vitro-produced shoots to Pro-Mix under intermittent mist in a greenhouse. Chemical names used: (E)-2-methyl-4-(1H-purin-6-ylamino)-2-buten-1-ol (zeatin); 1H-indole-3-acetic acid (IAA); N-1-furanyImethyl)-1-H-purin-6-amine (kinetin).