Al Leiter, Mike Hampton and Steve Woodard were tied for winning the most games in June 1999, with 5 wins.

	NAME	W	MONTH	L	W%	G	GS	ERA	SO	CG	SHO	SV	IP	H	ER	R	HR	BB	HBP	GF	IBB	TBF	WP	K/9	BB/9	K/BB	HR/9	K%	BB%	WHIP	BABIP	RA	H/9
1	Al Leiter A. Leiter	5	June 1999	0	1.000	5	5	2.62	30	0	0	0	34.1	27	10	10	0	12	0	0	0	136	1	7.86	3.15	2.50	0.00	22.1	8.8	1.14	.287	2.62	7.08
2	Mike Hampton M. Hampton	5	June 1999	1	.833	6	6	3.38	28	0	0	0	42.2	39	16	19	2	14	3	0	0	178	1	5.91	2.95	2.00	0.42	15.7	7.9	1.24	.282	4.01	8.23
3	Steve Woodard S. Woodard	5	June 1999	0	1.000	7	6	2.95	27	0	0	0	39.2	41	13	14	7	6	2	0	1	164	0	6.13	1.36	4.50	1.59	16.5	3.7	1.18	.279	3.18	9.30
4	Charles Nagy C. Nagy	4	June 1999	1	.800	5	5	3.66	14	0	0	0	32.0	33	13	17	4	9	1	0	2	137	1	3.94	2.53	1.56	1.13	10.2	6.6	1.31	.266	4.78	9.28
5	Orlando Hernandez O. Hernandez	4	June 1999	1	.800	5	5	2.00	18	1	1	0	36.0	28	8	10	1	11	2	0	0	147	0	4.50	2.75	1.64	0.25	12.2	7.5	1.08	.235	2.50	7.00
6	Hideo Nomo H. Nomo	4	June 1999	0	1.000	5	5	5.12	31	0	0	0	31.2	31	18	18	5	17	1	0	0	140	3	8.81	4.83	1.82	1.42	22.1	12.1	1.52	.302	5.12	8.81
7	Kevin Brown K. Brown	4	June 1999	2	.667	6	6	5.08	26	0	0	0	39.0	43	22	27	5	8	1	0	0	165	0	6.00	1.85	3.25	1.15	15.8	4.8	1.31	.304	6.23	9.92
8	Pedro Martinez P. Martinez	4	June 1999	1	.800	5	5	2.25	48	1	0	0	36.0	23	9	9	2	6	1	0	1	135	1	12.00	1.50	8.00	0.50	35.6	4.4	0.81	.269	2.25	5.75
9	Paul Byrd P. Byrd	4	June 1999	1	.800	6	6	2.76	20	0	0	0	42.1	37	13	17	2	14	5	0	0	185	1	4.25	2.98	1.43	0.43	10.8	7.6	1.20	.243	3.61	7.87
10	Roger Clemens R. Clemens	4	June 1999	2	.667	6	6	4.95	39	1	1	0	36.1	49	20	21	5	13	1	0	0	168	0	9.66	3.22	3.00	1.24	23.2	7.7	1.71	.400	5.20	12.14
11	Orel Hershiser O. Hershiser	4	June 1999	1	.800	6	6	2.97	20	0	0	0	36.1	32	12	12	1	13	1	0	0	151	1	4.95	3.22	1.54	0.25	13.2	8.6	1.24	.267	2.97	7.93
12	Jason Schmidt J. Schmidt	4	June 1999	2	.667	6	6	4.10	30	0	0	0	41.2	45	19	20	4	13	1	0	0	180	0	6.48	2.81	2.31	0.86	16.7	7.2	1.39	.311	4.32	9.72
13	Mike Sirotka M. Sirotka	4	June 1999	2	.667	6	6	3.79	21	0	0	0	38.0	51	16	20	4	5	1	0	0	169	0	4.97	1.18	4.20	0.95	12.4	3.0	1.47	.341	4.74	12.08
14	Randy Wolf R. Wolf	3	June 1999	0	1.000	4	4	3.80	25	0	0	0	23.2	22	10	11	4	11	0	0	0	102	2	9.51	4.18	2.27	1.52	24.5	10.8	1.39	.290	4.18	8.37
15	Tim Hudson T. Hudson	3	June 1999	1	.750	5	5	2.81	33	0	0	0	32.0	35	10	11	1	14	2	0	0	141	1	9.28	3.94	2.36	0.28	23.4	9.9	1.53	.374	3.09	9.84
16	Mike Morgan M. Morgan	3	June 1999	1	.750	5	5	3.55	11	1	0	0	33.0	27	13	13	5	12	0	0	0	133	0	3.00	3.27	0.92	1.36	8.3	9.0	1.18	.210	3.55	7.36
17	Pedro Astacio P. Astacio	3	June 1999	1	.750	5	5	5.81	30	1	0	0	31.0	39	20	24	8	12	2	0	1	144	0	8.71	3.48	2.50	2.32	20.8	8.3	1.65	.337	6.97	11.32
18	Kevin Millwood K. Millwood	3	June 1999	1	.750	5	5	3.94	23	0	0	0	32.0	24	14	17	6	10	1	0	1	130	2	6.47	2.81	2.30	1.69	17.7	7.7	1.06	.200	4.78	6.75
19	Kent Bottenfield K. Bottenfield	3	June 1999	1	.750	5	5	2.45	30	0	0	0	33.0	22	9	12	3	14	2	0	0	137	0	8.18	3.82	2.14	0.82	21.9	10.2	1.09	.216	3.27	6.00
20	Greg Maddux G. Maddux	3	June 1999	2	.600	5	5	2.52	25	0	0	0	35.2	34	10	13	1	7	1	0	1	144	1	6.31	1.77	3.57	0.25	17.4	4.9	1.15	.300	3.28	8.58
21	Jim Parque J. Parque	3	June 1999	0	1.000	5	5	2.76	21	1	0	0	32.2	32	10	15	3	13	3	0	0	143	0	5.79	3.58	1.62	0.83	14.7	9.1	1.38	.282	4.13	8.82
22	Kirk Rueter K. Rueter	3	June 1999	1	.750	5	5	3.58	14	1	0	0	32.2	33	13	13	2	7	0	0	0	131	1	3.86	1.93	2.00	0.55	10.7	5.3	1.22	.287	3.58	9.09
23	Brian Bohanon B. Bohanon	3	June 1999	2	.600	6	6	9.55	20	0	0	0	33.0	54	35	36	7	16	2	0	0	163	1	5.45	4.36	1.25	1.91	12.3	9.8	2.12	.398	9.82	14.73
24	David Cone D. Cone	3	June 1999	1	.750	5	5	3.41	25	0	0	0	34.1	29	13	14	4	13	3	0	1	145	1	6.55	3.41	1.92	1.05	17.2	9.0	1.22	.250	3.67	7.60
25	Tom Glavine T. Glavine	3	June 1999	1	.750	5	5	3.60	22	0	0	0	35.0	31	14	14	2	14	0	0	3	148	0	5.66	3.60	1.57	0.51	14.9	9.5	1.29	.264	3.60	7.97