Peritoneal tuberculosis is an important health concern in parts of the world where its prevalence is still high. Peritoneum is an uncommon site of extra pulmonary infection and the risk is increased in patients with cirrhosis, HIV infection, diabetes mellitus, underlying malignancy, following treatment with anti-tumor necrosis factor (TNF) agents, and in patients undergoing continuous ambulatory peritoneal dialysis (CAPD) [
1,
9]. Infection most commonly results from reactivation of latent tuberculous foci in the peritoneum that were established following hematogenous spread from a primary lung focus [
1]. Less frequently the organisms can enter the peritoneal cavity transmurally from an infected small intestine or contiguously from tuberculous salpingitis [
10]. Although the patient had no direct contact history or any of the listed predisposing factors, Sri Lanka is a country with high background prevalence, and she may have had primary subclinical infection with hematogenous spread and subsequent reactivation. According to the available literature the majority of patients present with ascites and constitutional symptoms such as anorexia, fever and loss of weight [
2,
11,
12]. It is more prevalent in females and seen more commonly in the third and fourth decades of life [
2,
12]. Portal vein thrombosis is a rare manifestation of the disease and has been described mainly in case reports [
3‐
5]. A high index of suspicion is needed for diagnosis of peritoneal tuberculosis and it should be included in the differential diagnosis of unexplained lymphocytic ascites with SAAG < 1.1 g/dl [
11] In contrast , though lymphocytic predominant, ascites was a transudate in this case even in the absence of concomitant portal hypertension or cirrhosis. This again is unusual but the study carried out by Manohar A et al. describes such presentations [
2]. Examination of the ascitic fluid including staining for acid fast bacilli is known to have a very low yield and the mortality associated with waiting for culture results has been demonstrated to be high [
6]. In contrast, peritoneal biopsy either by laparoscopy or laparotomy has been proven in several studies to be the gold standard [
6‐
8]. In this patient all diagnostic modalities including tuberculosis genome detection tests on ascitic fluid were inconclusive making the diagnosis a dilemma. But high index of suspicion and peritoneal sampling through laparoscopy ultimately led to the correct diagnosis. In the majority the standard treatment as for pulmonary tuberculosis leads to rapid clinical improvement [
13].