Ultrasound fine needle aspiration cytology (US-FNAC) represents the most effective test available to distinguish between benign and malignant thyroid nodules, with an accuracy approaching 95%. The major limit of this procedure it is the rate of inadequate specimens which is reported to be from 10% to 31%. Also because cost considerations have always been important and have recently become even more relevant for clinical guidelines in many countries, it is desirable to limit the number of inadequate samples. Recently, we have shown that the use of stylet needles greatly reduces inadequate cytological specimens in thyroid nodules with an intranodular vascular pattern. With the aim to improve our previous results, we have extended our procedure to all thyroid solid nodules. Between February 2004 and March 2006, 312 consecutive patients with thyroid nodule without intranodular vascular pattern at color-Doppler evaluation were enrolled in this prospective study. US-FNAC was performed by two different 25 gauge needles (Neolus [Ns] and Yale Spinal [YS]), and the two procedures were performed in alternate sequence on consecutive patients. Adequate specimens were observed in 145 (92.9%) and 153 (98%) nodules respectively investigated by Ns and in YS (p<0.005). The total cost to obtain a cytological diagnosis by Ns was of euro 12210.2 (156+12 repeated US-FNAC), whereas it was of euro 12449.7 by YS (156+3 repeated US-FNAC). Our data suggest that spinal needles are associated with a low proportion of inadequate FNAC, without increase of total direct cost, considering also the number of FNAC repetitions needed; therefore, their routine use could be taken into account.