Uptake of phosphorus (P) by cotton crops demonstrated an excellent correlation with lint yield. Despite high levels of P fertiliser being applied, crops in Kununurra took up less than 15 kg P/ha and failed to produce lint yields greater than 8 bales/ha. Lint yields and P uptake at Narrabri however were considerably greater, indicating that another factor was preventing P uptake at Kununurra and thus limiting yield potential. These results confirm the P fertiliser recommendations suggested in the NUTRIpak manual.