The effect of plant growth regulators (PGRs) on the accumulation of the alkaloid camptothecin (CPT) and its analogue 10-hydroxycamptothecin (HCPT) in tender leaves of Camptotheca acuminata saplings was studied. In screening experiments for PGRs, 40 mg/L dose of thiourea, triacontanol, and ascorbic acid (VC) had no positive effects on the accumulation of the alkaloids. However, treatments with 40 mg/L of chlormequat chloride (CCC), choline chloride, paclobutrazol (PBZ), and daminozide (B9) induced CPT and HCPT accumulation in both pre-harvest and postharvest stages. On that basis, five levels of PGRs at 0, 20, 40, 60, 80 mg/L were sprayed on tender leaves of C. acuminata saplings at pre-harvest and postharvest stages. Treatment by 40 mg/L CCC dramatically enhanced HCPT production by 308 % in pre-harvest, treatment by 60 mg/L CCC enhanced HCPT production by 100 % in postharvest. Spraying the leaves with 60 mg/L choline chloride resulted in 94 % increase of CPT and spraying with 40 mg/L of the PGRs reached 167 % increase of HCPT in the pre-harvest treatment, respectively; treatments with 60 mg/L choline chloride resulted in 64 % increase of CPT and 525 % increase of HCPT in postharvest, respectively. 52 % increase of CPT and 86 % increase of HCPT in pre-harvest, 22 % increase of CPT and 33 % increase of HCPT in postharvest were obtained by spraying leaves with 60 mg/L PBZ. Treatments with 40 mg/L B9 had the highest impact on CPT (12 % increase in pre-harvest, 11 % increase in postharvest) and HCPT (167 % increase in pre-harvest, 173 % increase in postharvest) accumulation. The optimal PGR for obtaining the highest levels of CPT and HCPT was treatment with 60 mg/L choline chloride. In most case, the pre-harvest treatment was better than the postharvest one. These preliminary results suggest that the application of PGRs may be a useful and feasible method to increase CPT and HCPT levels in C. acuminata. © 2012 Springer Science+Business Media B.V.