For a long time, surgical removal of somatotropinoma using the transsphenoidal approach has been the first stage of treatment in most acromegaly patients. For the past decades, the efficacy criteria for surgical treatment of acromegaly have significantly changed, which requires appropriate correction. Purpose. We aimed to evaluate the results of transsphenoidal adenomectomy in acromegaly patients using various criteria for disease remission. Material and methods. The study included patients with newly diagnosed acromegaly who underwent transnasal transsphenoidal endoscopic adenomectomy performed by a single neurosurgeon. The surgical treatment outcomes were evaluated 6 months after operative intervention based on levels of IGF-1, OGTT, and GH. The obtained data were analyzed using different threshold values for the level of GH nadir during OGTT: criteria A <2.0 ng/ml, criteria B <1.0 ng/ml, and criteria C <0.4 ng/ml to assess acromegaly remission, along with matching of the IGF-1 level to the reference range for a given gender and age. Results. The study included 70 patients (52 females and 18 males) with a mean age of 52.2±11.5 years (29 to 73 years). The baseline IGF-1 level exceeded the upper limit of the reference range 3.3±1.4 (1.1―7.3)-fold, on average. The baseline mean basal GH level was 34.2±41.7 (1.2―192.0) ng/ml. The mean pituitary adenoma size was 16.7±8.6 (4.3—46.0) mm; 18 (26%) out of 70 patients had pituitary microadenoma, and 52 (74%) patients had macroadenoma. Six months after surgery, acromegaly remission met criteria A in 47 (67%) patients, criteria B in 28 (40%) patients, and criteria C in 18 (26%) patients. Conclusion. Our findings demonstrate that evaluation of transsphenoidal adenomectomy outcomes in treatment of acromegaly patients depends on the criteria chosen for assessing remission. This feature should be considered when comparing outcomes of surgical treatment for acromegaly in different years. Probably, introduction of the 2010 criteria should be accompanied by revision of the previous remission indicators.